The official website of the National Hockey League named Chris Osgood as the Second Team All-Star goalie on the NHL's All-Decade Team (hat tip to an anonymous poster on this blog for passing along the link).
That is so mind-boggling that it really shouldn't require much further comment for any rational individual. But if you want to see some numbers just to drill the point home, here are the GAAs of Chris Osgood and Roberto Luongo in both the regular season and the playoffs from 1999-00 to 2009-10:
Regular Season: Osgood 2.56, Luongo 2.56
Playoffs: Osgood 2.05, Luongo 2.09
Even if one was so crazy as to use goal prevention as the sole criterion, it's still barely possible to make the argument for Osgood over Luongo, when you consider that Luongo played in a lot more games. Think for more than a nanosecond about their respective teammates and team situations and it's completely obvious who is far better.
If you want to argue about the value of save percentages for someone like Martin Brodeur, who brings more to the table than just stopping pucks that's fine, but this is Chris Osgood. Over the last decade Osgood's numbers read .912 at EV and .871 on the PK. Luongo's .929 at EV and .887 on the PK. And we're talking about a sample size of over 13,000 shots for Osgood and nearly 18,000 shots for Luongo, i.e. no doubt at all that there is a massive gulf between the two goalies.
Multiply the save percentage differential over Luongo's workload, and you get a difference of 275 goals, or nearly 30 goals per season. That's the equivalent of something like 50-55 wins. A team would be 10 points better in the standings every year with Luongo in net than with Osgood. On a per-game basis, that's a difference of about half a goal per game. Yet somehow a difference in playoff winning percentage of .073 between the two goalies is enough to make up for all of that.
Basically, this guy is saying that the scoring proficiency of a goalie's team means an awful lot more than saving an extra half a goal per game, based on the time-worn journalistic principle of assigning all team results to the account of their goaltender. Yet I'm sure nobody would dare rank one skater ahead of another if the first guy had averaged 30 fewer points per season than the other guy for an entire decade, regardless of any difference between them in terms of Cups or team success.
For illustrative purposes, here are the players who averaged 0.5 PPG less over the past 10 years than All-Decade First Team All-Star Joe Sakic:
Pierre-Marc Bouchard
Jonathan Cheechoo
Ulf Dahlen
Joe Pavelski
Gary Roberts
Todd White
And the same thing for fellow First Team All-Star Jarome Iginla:
Chris Higgins
Jan Hlavac
Bobby Holik
Sami Kapanen
Steve Konowalchuk
Sergei Zholtok
Now obviously scoring totals are not complete assessments of player values, but I think the point is pretty obvious. I'm not sure Osgood would make my Fifteenth All-Decade Team, as I'd take any of Luongo, Brodeur, Giguere, Kiprusoff, Hasek, Roy, Vokoun, Kolzig, Belfour, Nabokov, Lundqvist, Turco, Roloson, Khabibulin, Thomas or Theodore ahead of him. Maybe a couple of others as well.
Saturday, December 26, 2009
Saturday, December 19, 2009
Monday, December 14, 2009
Goalie and Faceoffs
Some of the most interesting new statistics introduced by stats guys in the blogosphere have been numbers that track how many defensive and offensive zone faceoffs players are put on the ice for. For skaters, this helps adjust for the way they are being used by their coach, since for example it is an advantage for an offensive player to start their shift in the other team's end rather than having to move the puck 180 feet down the ice to get it into a scoring position. Faceoff numbers can also be used to measure which players are driving possession, by seeing whether a player ends their shift more often in the offensive or defensive zone.
I haven't seen anyone apply these numbers yet to goalies. Since goalies don't change lines, the starting and ending shift numbers are of course meaningless. However, on many shots goalies have the opportunity to either freeze or play the puck, and that choice affects the number of defensive zone draws their teams face. Also, if certain goalies are able to contribute to their teams in other ways, such as for example through their puckhandling skills, then it might show up by their team taking more draws at the other end of the rink.
Vic Ferrari at timeonice has the faceoff zone start numbers for every player in the league last year, including goalies. I'll stick to the convention used by Gabe Desjardins at Behind the Net where he has the offensive faceoff percentage for all players, a number calculated by ignoring the neutral zone faceoffs and dividing the number of offensive zone faceoffs by the total number of draws in offensive and defensive zone combined.
The correlation between the offensive faceoff percentage for starters and their backups was 0.51, which suggests that the rest of the team has a big impact on puck possession and faceoffs. That should be fairly uncontroversial. I'd expect with a bigger sample size for most of the backup goalies that number would be higher.
The correlation between offensive faceoff percentage and shots faced per 60 minutes was -0.57. I was expecting that relationship to be stronger, since all the Corsi evidence shows a big advantage to starting in the other team's zone, but again EV only for one season is a fairly small sample so there is likely a reasonable degree of luck in the numbers.
There were 9 teams that had a offensive faceoff percentage difference of 5% or more between their starting goalie and his backups. Here are the faceoff numbers for each of those teams, along with the offensive faceoff percentages and shots faced per 60 minutes:
Buffalo:
Ryan Miller: 480 def, 433 off, 47%, 30.9 SA/60
Backups: 254 def, 282 off, 53%, 31.2 SA/60
Edmonton:
Dwayne Roloson: 553 def, 513 off, 48%, 32.6 SA/60
Backups: 210 def, 240 off, 53%, 31.4 SA/60
Montreal:
Carey Price: 423 def, 409 off, 49%, 29.9 SA/60
Jaroslav Halak: 383 def, 269 off, 41%, 33.5 SA/60
New Jersey:
Martin Brodeur: 194 def, 268 off, 58%, 28.8 SA/60
Scott Clemmensen: 434 def, 353 off, 45%, 29.0 SA/60
Kevin Weekes: 154 def, 136 off, 47%, 30.1 SA/60
New York Rangers:
Henrik Lundqvist: 459 def, 665 off, 59%, 29.0 SA/60
Steve Valiquette: 90 def, 102 off, 53%, 30.7 SA/60
Ottawa:
Alex Auld: 322 def, 373 off, 54%, 28.0 SA/60
Backups: 390 def, 332 off, 46%, 28.3 SA/60
Philadelphia:
Martin Biron: 584 def, 484 off, 45%, 32.4 SA/60
Antero Niittymaki: 226 def, 230 off, 50%, 31.5 SA/60
San Jose:
Evgeni Nabokov: 510 def, 521 off, 51%, 27.1 SA/60
Brian Boucher: 150 def, 202 off, 57%, 26.2 SA/60
Toronto:
Vesa Toskala: 342 def, 366 off, 52%, 29.8 SA/60
Backups: 278 def, 370 off, 57%, 30.0 SA/60
The Price/Halak gap is interesting and appears to account for some of the shot differential between them, but I'm not sure how much it had to do with the goalies. I'd bet the split would be in the other direction if we were looking at this season's numbers, based on how Montreal has played in front of each of them in 2009-10. Most of the others either involve backups who didn't play very much or goalies who I wouldn't expect to have much of an effect on faceoffs, although there is one notable exception.
The biggest gap between any starter and backup, by far, is in New Jersey. Knowing what we know about those goalies, I'd say that these numbers suggest a real effect. In most starter/backup scenarios, we have to at least consider the possibility of strength of schedule being a factor, but that wasn't the case here as Clemmensen was an injury replacement for Brodeur. The Devils weren't performing exactly the same all the way through the season, but all three of their goalies had similar GAAs so it is likely that they played in fairly similar environments.
The numbers indicate that Brodeur is either helping shift the play to the other end of the ice or freezing the puck less often than the other goalies. Here are the faceoff numbers for New Jersey's goalies broken down per 60 minutes of EV play:
Brodeur: 8.6 def zone, 11.9 off zone
Clemmensen: 14.2 def zone, 11.6 off zone
Weekes: 15.4 def zone, 13.6 off zone
Brodeur keeps the puck moving a lot more than the other two (and indeed, he probably keeps it moving more than any other goalie in the league). However, the team did not take substantially more faceoffs at the other end of the rink, which makes it uncertain whether Brodeur's impact translates to the offensive side of the rink (although I would certainly like to see more data on this one).
Consistently giving the puck to teammates instead of allowing the opposing team to win control of it through a faceoff should help a team, and this may account for some of the observed shot differentials between Brodeur and his backup goalies. There are other possible benefits, such as creating more changes on the fly, which could be to the benefit of a smart bench coach who wants to get his matchups. I'd expect some tradeoff in terms of increased turnovers, but Brodeur is likely pretty efficient.
I think these results also shed a bit more light on the rebound numbers discussed earlier here that showed Clemmensen allowing a lower rate of rebound shots against than Brodeur. Given that Brodeur would have been playing the puck much more often and attempting to direct his rebounds rather than simply freezing the puck, that means he would have been facing many more opportunities to turn over the puck or for the other team to steal it and get a quick shot on goal. If Brodeur was aggressive in terms of directing rebounds and playing the puck while Clemmensen was conservative (and probably helped by a defence that gave extra attention to clearing the crease), then that would explain why Brodeur's numbers don't seem as good despite his superior skill. More opportunities usually mean more errors, no matter how good you are.
This is just a cursory look from one year's worth of data, but looking at a few more seasons' worth of data could help us better identify Brodeur's effect here and see whether any other goalies seem to have a tendency towards freezing or moving the puck.
I haven't seen anyone apply these numbers yet to goalies. Since goalies don't change lines, the starting and ending shift numbers are of course meaningless. However, on many shots goalies have the opportunity to either freeze or play the puck, and that choice affects the number of defensive zone draws their teams face. Also, if certain goalies are able to contribute to their teams in other ways, such as for example through their puckhandling skills, then it might show up by their team taking more draws at the other end of the rink.
Vic Ferrari at timeonice has the faceoff zone start numbers for every player in the league last year, including goalies. I'll stick to the convention used by Gabe Desjardins at Behind the Net where he has the offensive faceoff percentage for all players, a number calculated by ignoring the neutral zone faceoffs and dividing the number of offensive zone faceoffs by the total number of draws in offensive and defensive zone combined.
The correlation between the offensive faceoff percentage for starters and their backups was 0.51, which suggests that the rest of the team has a big impact on puck possession and faceoffs. That should be fairly uncontroversial. I'd expect with a bigger sample size for most of the backup goalies that number would be higher.
The correlation between offensive faceoff percentage and shots faced per 60 minutes was -0.57. I was expecting that relationship to be stronger, since all the Corsi evidence shows a big advantage to starting in the other team's zone, but again EV only for one season is a fairly small sample so there is likely a reasonable degree of luck in the numbers.
There were 9 teams that had a offensive faceoff percentage difference of 5% or more between their starting goalie and his backups. Here are the faceoff numbers for each of those teams, along with the offensive faceoff percentages and shots faced per 60 minutes:
Buffalo:
Ryan Miller: 480 def, 433 off, 47%, 30.9 SA/60
Backups: 254 def, 282 off, 53%, 31.2 SA/60
Edmonton:
Dwayne Roloson: 553 def, 513 off, 48%, 32.6 SA/60
Backups: 210 def, 240 off, 53%, 31.4 SA/60
Montreal:
Carey Price: 423 def, 409 off, 49%, 29.9 SA/60
Jaroslav Halak: 383 def, 269 off, 41%, 33.5 SA/60
New Jersey:
Martin Brodeur: 194 def, 268 off, 58%, 28.8 SA/60
Scott Clemmensen: 434 def, 353 off, 45%, 29.0 SA/60
Kevin Weekes: 154 def, 136 off, 47%, 30.1 SA/60
New York Rangers:
Henrik Lundqvist: 459 def, 665 off, 59%, 29.0 SA/60
Steve Valiquette: 90 def, 102 off, 53%, 30.7 SA/60
Ottawa:
Alex Auld: 322 def, 373 off, 54%, 28.0 SA/60
Backups: 390 def, 332 off, 46%, 28.3 SA/60
Philadelphia:
Martin Biron: 584 def, 484 off, 45%, 32.4 SA/60
Antero Niittymaki: 226 def, 230 off, 50%, 31.5 SA/60
San Jose:
Evgeni Nabokov: 510 def, 521 off, 51%, 27.1 SA/60
Brian Boucher: 150 def, 202 off, 57%, 26.2 SA/60
Toronto:
Vesa Toskala: 342 def, 366 off, 52%, 29.8 SA/60
Backups: 278 def, 370 off, 57%, 30.0 SA/60
The Price/Halak gap is interesting and appears to account for some of the shot differential between them, but I'm not sure how much it had to do with the goalies. I'd bet the split would be in the other direction if we were looking at this season's numbers, based on how Montreal has played in front of each of them in 2009-10. Most of the others either involve backups who didn't play very much or goalies who I wouldn't expect to have much of an effect on faceoffs, although there is one notable exception.
The biggest gap between any starter and backup, by far, is in New Jersey. Knowing what we know about those goalies, I'd say that these numbers suggest a real effect. In most starter/backup scenarios, we have to at least consider the possibility of strength of schedule being a factor, but that wasn't the case here as Clemmensen was an injury replacement for Brodeur. The Devils weren't performing exactly the same all the way through the season, but all three of their goalies had similar GAAs so it is likely that they played in fairly similar environments.
The numbers indicate that Brodeur is either helping shift the play to the other end of the ice or freezing the puck less often than the other goalies. Here are the faceoff numbers for New Jersey's goalies broken down per 60 minutes of EV play:
Brodeur: 8.6 def zone, 11.9 off zone
Clemmensen: 14.2 def zone, 11.6 off zone
Weekes: 15.4 def zone, 13.6 off zone
Brodeur keeps the puck moving a lot more than the other two (and indeed, he probably keeps it moving more than any other goalie in the league). However, the team did not take substantially more faceoffs at the other end of the rink, which makes it uncertain whether Brodeur's impact translates to the offensive side of the rink (although I would certainly like to see more data on this one).
Consistently giving the puck to teammates instead of allowing the opposing team to win control of it through a faceoff should help a team, and this may account for some of the observed shot differentials between Brodeur and his backup goalies. There are other possible benefits, such as creating more changes on the fly, which could be to the benefit of a smart bench coach who wants to get his matchups. I'd expect some tradeoff in terms of increased turnovers, but Brodeur is likely pretty efficient.
I think these results also shed a bit more light on the rebound numbers discussed earlier here that showed Clemmensen allowing a lower rate of rebound shots against than Brodeur. Given that Brodeur would have been playing the puck much more often and attempting to direct his rebounds rather than simply freezing the puck, that means he would have been facing many more opportunities to turn over the puck or for the other team to steal it and get a quick shot on goal. If Brodeur was aggressive in terms of directing rebounds and playing the puck while Clemmensen was conservative (and probably helped by a defence that gave extra attention to clearing the crease), then that would explain why Brodeur's numbers don't seem as good despite his superior skill. More opportunities usually mean more errors, no matter how good you are.
This is just a cursory look from one year's worth of data, but looking at a few more seasons' worth of data could help us better identify Brodeur's effect here and see whether any other goalies seem to have a tendency towards freezing or moving the puck.
Monday, December 7, 2009
Why Offence Rules the New NHL
"Defence wins championships" is a familiar cliche that is thrown around as a truth in not only hockey circles, but by fans of virtually every team sport. At some points in hockey history it may have been true, but I believe the game has changed. In the new NHL, the evidence suggests that offence wins championships.
First of all, I'll give the small sample size warning to everything that I'm about to post. Past results do not guarantee future performance and so on. I tend to believe the numbers show a real effect since regular season results have generally fallen in line, but I'm going to be focusing on playoff results only which means that the sample is limited to 60 playoff series over the last 4 seasons.
Secondly, I'm ignoring all shootouts here. Goals for and goals against mean actual goals, not the goal awarded in the standings to the team that won the shootout. I counted all games that went into a shootout as ties for both teams, so because of that a few times I considered a team that finished lower in the standings to have had a better record than their opponent. This approach makes sense to me since shootouts don't happen in the playoffs.
It is important to realize that in the playoffs nothing happens with a high degree of certainty. Upsets regularly happen in short series. Just to establish a baseline, over the period from 1955-2009 the team with the better regular season winning percentage has won 65% of the playoff series. Since the lockout the percentage has fallen to 61%, which likely reflects the higher level of parity in today's game.
If the better overall team wins 61% of the time, how does the better offensive team do? Answer: The team with more goals scored has actually done even better, winning 37 of the last 60 series (62%). That's a much better success rate than the team with fewer goals allowed, which has won just 27 series (45%).
Often the same team will be better in both categories. For example, the 2008 Detroit Red Wings had better regular season offensive and defensive numbers than all four of their playoff opponents. Let's look only at series when a team with more goals scored plays against a team with fewer goals against, the classic offensive team vs. defensive team scenario. In those matchups, the stronger offensive team has won 24 out of 38 times (63%).
The numbers also show the value of looking at a team's win threshold. The team with the better win threshold won 38 out of 60 series (63%). Win threshold has been a better predictor of success since 2006 than a team's overall record or number of goals scored. As you can infer from that result, a team with a higher win threshold was slightly more likely to win than an opponent with a lower win threshold even when the latter had a better win/loss record, although this advantage was slight (11/21, 52%).
When we focus on goaltending, we also see that the post-lockout playoffs have been determined primarily by the play of skaters, rather than by the play of the masked men. The team with the better regular season save percentage has won just 25 out of 60 series (42%). When a team with a better save percentage has played against a team with a better record, the team with the better goaltending won just 7 out of 25 series.
If you look at each position individually then goalie is the most important position in hockey, but the 18 skaters as a group are collectively much more important than the goalie. A good measure of the effectiveness of the skaters is a team's win threshold. Since the lockout, when a team with a better win threshold went up against a team with a better save percentage, the team with the better skaters won 26 out of 39 times (67%). Given the uncertainty of playoff results in hockey, that is a very high probability.
There is another cliche that goes something like, "In the playoffs you don't need a great goalie, you just need a hot goalie". If you have a dominant team then you might not even need that, but for most teams that is probably not far from the truth. The abundance of good goalies in today's NHL means that a lot of teams have a goalie that is capable of excellent play for a month or two. The best goalies are not able to be the difference makers that they perhaps once were, and that means that goaltending ranks well behind a team's offensive ability in terms of predicting their success.
First of all, I'll give the small sample size warning to everything that I'm about to post. Past results do not guarantee future performance and so on. I tend to believe the numbers show a real effect since regular season results have generally fallen in line, but I'm going to be focusing on playoff results only which means that the sample is limited to 60 playoff series over the last 4 seasons.
Secondly, I'm ignoring all shootouts here. Goals for and goals against mean actual goals, not the goal awarded in the standings to the team that won the shootout. I counted all games that went into a shootout as ties for both teams, so because of that a few times I considered a team that finished lower in the standings to have had a better record than their opponent. This approach makes sense to me since shootouts don't happen in the playoffs.
It is important to realize that in the playoffs nothing happens with a high degree of certainty. Upsets regularly happen in short series. Just to establish a baseline, over the period from 1955-2009 the team with the better regular season winning percentage has won 65% of the playoff series. Since the lockout the percentage has fallen to 61%, which likely reflects the higher level of parity in today's game.
If the better overall team wins 61% of the time, how does the better offensive team do? Answer: The team with more goals scored has actually done even better, winning 37 of the last 60 series (62%). That's a much better success rate than the team with fewer goals allowed, which has won just 27 series (45%).
Often the same team will be better in both categories. For example, the 2008 Detroit Red Wings had better regular season offensive and defensive numbers than all four of their playoff opponents. Let's look only at series when a team with more goals scored plays against a team with fewer goals against, the classic offensive team vs. defensive team scenario. In those matchups, the stronger offensive team has won 24 out of 38 times (63%).
The numbers also show the value of looking at a team's win threshold. The team with the better win threshold won 38 out of 60 series (63%). Win threshold has been a better predictor of success since 2006 than a team's overall record or number of goals scored. As you can infer from that result, a team with a higher win threshold was slightly more likely to win than an opponent with a lower win threshold even when the latter had a better win/loss record, although this advantage was slight (11/21, 52%).
When we focus on goaltending, we also see that the post-lockout playoffs have been determined primarily by the play of skaters, rather than by the play of the masked men. The team with the better regular season save percentage has won just 25 out of 60 series (42%). When a team with a better save percentage has played against a team with a better record, the team with the better goaltending won just 7 out of 25 series.
If you look at each position individually then goalie is the most important position in hockey, but the 18 skaters as a group are collectively much more important than the goalie. A good measure of the effectiveness of the skaters is a team's win threshold. Since the lockout, when a team with a better win threshold went up against a team with a better save percentage, the team with the better skaters won 26 out of 39 times (67%). Given the uncertainty of playoff results in hockey, that is a very high probability.
There is another cliche that goes something like, "In the playoffs you don't need a great goalie, you just need a hot goalie". If you have a dominant team then you might not even need that, but for most teams that is probably not far from the truth. The abundance of good goalies in today's NHL means that a lot of teams have a goalie that is capable of excellent play for a month or two. The best goalies are not able to be the difference makers that they perhaps once were, and that means that goaltending ranks well behind a team's offensive ability in terms of predicting their success.
Wednesday, December 2, 2009
Clutch Play
"TCG's other big problem is that he completely ignores the human element of sport, and approaches all statistical problems from the assumption that players perform the same regardless of game situation, again without ever really grappling with the problem. It is essentially a hockey version of Moneyball, Billy Beane's now comical baseball analysis which included the theory that there is no such thing as clutch hitting...I find attempts to erase the human element of sport under a pile of statistics not only patently false, but also vaguely disgusting." (HFBoards)
I just wanted to post a few words about my outlook on clutch play. The poster above is essentially correct in my base assumption regarding clutch performance in hockey players. However, I don't think it's fair to say I've never grappled with the problem. I simply think that the high degree of uncertainty means that it does not make sense to use clutch performance as an evaluative tool for goalies. Here are the six primary reasons:
1. Most of hockey is played with the score close. Allowing a goal against in a close game results in a significant downgrade in a team's win probability, and therefore most of a goalie's workload should be considered to be a clutch situation. From that, it follows that a goalie's overall performance should closely approximate his clutch performance, since most of the sample comes from situations with a high penalty for allowing a goal against.
2. If we define clutch situations more narrowly, we run into small sample size issues. For example, if we were to evaluate goalies based entirely on their performance in third periods in the playoffs, then we only have several hundred shots to work with even for experienced netminders. A more common split is to simply discuss regular season performance and playoff performance separately, but for the most part over a larger sample size the two results converge, or are generally within a typical margin of error for the size of the sample. Playoff results are also fraught with additional perils, including extreme opposition effects, a different style of play, and greater playing-to-the-score effects.
3. The best way to evaluate a method or statistic is to see how well it predicts the future. If we want to include clutch play in our predictions for active netminders, then sample size is even more of a concern. It is a simple fact of random chance and the variability of athletic endeavours that some goalies are going to start their playoff careers hot while others start their playoff careers cold, regardless of their level of talent, preparation or mental fortitude. Without a large sample size to work with, we're essentially guessing at this point whether someone like Cam Ward has a true ability to raise his game in important situations or whether he had a couple of well-timed hot streaks. If he continues to play on a marginally talented team that frequently misses the playoffs, we may never know with a high degree of confidence which viewpoint is correct.
4. Players and teams have the option of changing their style of play, their matchups, their shoot/pass tendencies, and their offensive/defensive bias to match the game situation. Goalies do not have those same strategic options. This suggests that changes in results or percentages in response to the game situation are primarily driven by players, not goalies.
5. Nearly every goalie who has been identified as clutch by subjective evaluators played on a dominant team. That correlation certainly suggests that many observers are conflating team effects with goaltender performance. It is possible that they are correct, but it does not seem very probable, given that on the whole team strength is a much better predictor of playoff success than goalie strength. If there were goalies who played on weak teams who did not have significant team success yet were universally praised as clutch, then I would have more confidence in the ability of observers to rate "clutchness".
6. Subjective evaluations of goalies often strongly emphasize a goalie's performance in important situations, his team success, and whether or not someone believes he is a "winner". It is conventional hockey wisdom that you need a clutch goalie to win and that the best goalies win the most games. Therefore, it seems extremely likely that there should be a selection bias against goalies who can't perform under pressure, that scouts will pick out the most clutch goalies to advance to higher levels of play. If a goalie who is in truth a "choker" or a "loser" does make it all the way to the best league in the world, then that would reflect somewhat poorly on the ability of observers to subjectively evaluate clutch play.
In summary, I'm not a clutch play disbeliever, merely a clutch play skeptic. I have done studies of clutch performance because I think it is a worthwhile topic to investigate, but I don't think the evidence suggests it is particularly significant or that it is accurately estimated by observers. I'm certainly not saying that sports psychologists are quacks, or that all athletes perform at exactly the same level in every situation. Players are indeed human, and there are too many top-level athletes who failed under pressure to discount the human element entirely. However, I think we need to focus primarily on the most significant data, and I see NHL goaltending as an area where major clutch differences are structurally unlikely (see points 1, 4 and 6 above). We also have to be very careful about poor logic when switching back and forth from the general case to the specific case, e.g. some athletes choke, Goalie A choked in a big game, therefore Goalie A is a choker who will always choke.
Let's assume there is some small variance in clutch skill among NHL goalies. Precisely measuring that skill will be very difficult, whether you are evaluating players subjectively, objectively, or using both methods. Either way you are going to make mistakes, because chance happens and the future is unknown. If you want to be like a television broadcaster and subjectively praise players for their mental toughness and because "all they do is win", then you are going to hype some guys who simply went on a hot streak and have nothing but regression to the mean in their future. You're also going to dump on some players for their lack of fortitude who, unbeknownst to you, are going to tear up the league in future playoff seasons.
On the other hand, if you view the world the way I do, you run the risk of failing to correctly praise a player as clutch, or at least you won't do so until their careers are mostly over and they have proven that they have that ability. You will also continue to predict great things for players who have good overall records but have poor clutch performances in their early careers. Some of these players might continue to perform poorly under pressure, but many of them will see their future pressure performances improve to match their overall ability.
If someone thinks that this perspective is promoting an agenda or in some way ignoring evidence, I'd like to point out that I took the same approach on shot prevention effects. I always thought there was a small effect, but I thought it was likely fairly insignificant and I wasn't going to commit to anything at all until I had evidence of what it was.
Was I wrong to state that goalies have no effect on shots against? Absolutely, as I think there is some very good evidence that goalies can affect the number of shots against, and the observed variance among NHL goalies seems to be about 1 shot above or below average. However, there are tons of people (including Martin Brodeur himself) who are demonstrably wrong on the other side of the equation because they overestimate the effect. Guessing too high is just as wrong as guessing too low. And by doing some in-depth research on the issue from my devil's advocate position and debating others who disagreed with me, I think we've come to greater learning than we otherwise would have if I'd merely accepted the consensus opinion or came to some quick subjective estimate and left it there.
Similarly, it's highly probable that I would be wrong to state that there is absolutely no difference in clutch skill among NHL goalies. However, in the presence of uncertainty that's still the position I am generally going to take, because I don't know exactly where to draw the line and I think that most people are drawing theirs too far on the opposite side of the true marker. That makes us both wrong, but my bet is that I'm closer to being right.
It's doubtful we'll ever develop perfect metrics or track them perfectly, and even if we do there are still going to be some limitations like being constrained by sample size. In the great clutch debate, that means it is likely always going to come down to picking which error you want to make. I'd rather assume a player is not clutch and wait for proof that they are, then assume that they are and wait for proof that they aren't. I think the general correlation between regular season and playoff performance, and the observed regression to the mean of many players who at one point or another were considered playoff over- or underachievers makes my position the one that is less likely to make mistakes. I am quite aware that there will probably still be mistakes, but I'm willing to accept the trade-off. And if we can ever prove the magnitude of clutch skill for NHL goalies, then I will update my position accordingly.
I just wanted to post a few words about my outlook on clutch play. The poster above is essentially correct in my base assumption regarding clutch performance in hockey players. However, I don't think it's fair to say I've never grappled with the problem. I simply think that the high degree of uncertainty means that it does not make sense to use clutch performance as an evaluative tool for goalies. Here are the six primary reasons:
1. Most of hockey is played with the score close. Allowing a goal against in a close game results in a significant downgrade in a team's win probability, and therefore most of a goalie's workload should be considered to be a clutch situation. From that, it follows that a goalie's overall performance should closely approximate his clutch performance, since most of the sample comes from situations with a high penalty for allowing a goal against.
2. If we define clutch situations more narrowly, we run into small sample size issues. For example, if we were to evaluate goalies based entirely on their performance in third periods in the playoffs, then we only have several hundred shots to work with even for experienced netminders. A more common split is to simply discuss regular season performance and playoff performance separately, but for the most part over a larger sample size the two results converge, or are generally within a typical margin of error for the size of the sample. Playoff results are also fraught with additional perils, including extreme opposition effects, a different style of play, and greater playing-to-the-score effects.
3. The best way to evaluate a method or statistic is to see how well it predicts the future. If we want to include clutch play in our predictions for active netminders, then sample size is even more of a concern. It is a simple fact of random chance and the variability of athletic endeavours that some goalies are going to start their playoff careers hot while others start their playoff careers cold, regardless of their level of talent, preparation or mental fortitude. Without a large sample size to work with, we're essentially guessing at this point whether someone like Cam Ward has a true ability to raise his game in important situations or whether he had a couple of well-timed hot streaks. If he continues to play on a marginally talented team that frequently misses the playoffs, we may never know with a high degree of confidence which viewpoint is correct.
4. Players and teams have the option of changing their style of play, their matchups, their shoot/pass tendencies, and their offensive/defensive bias to match the game situation. Goalies do not have those same strategic options. This suggests that changes in results or percentages in response to the game situation are primarily driven by players, not goalies.
5. Nearly every goalie who has been identified as clutch by subjective evaluators played on a dominant team. That correlation certainly suggests that many observers are conflating team effects with goaltender performance. It is possible that they are correct, but it does not seem very probable, given that on the whole team strength is a much better predictor of playoff success than goalie strength. If there were goalies who played on weak teams who did not have significant team success yet were universally praised as clutch, then I would have more confidence in the ability of observers to rate "clutchness".
6. Subjective evaluations of goalies often strongly emphasize a goalie's performance in important situations, his team success, and whether or not someone believes he is a "winner". It is conventional hockey wisdom that you need a clutch goalie to win and that the best goalies win the most games. Therefore, it seems extremely likely that there should be a selection bias against goalies who can't perform under pressure, that scouts will pick out the most clutch goalies to advance to higher levels of play. If a goalie who is in truth a "choker" or a "loser" does make it all the way to the best league in the world, then that would reflect somewhat poorly on the ability of observers to subjectively evaluate clutch play.
In summary, I'm not a clutch play disbeliever, merely a clutch play skeptic. I have done studies of clutch performance because I think it is a worthwhile topic to investigate, but I don't think the evidence suggests it is particularly significant or that it is accurately estimated by observers. I'm certainly not saying that sports psychologists are quacks, or that all athletes perform at exactly the same level in every situation. Players are indeed human, and there are too many top-level athletes who failed under pressure to discount the human element entirely. However, I think we need to focus primarily on the most significant data, and I see NHL goaltending as an area where major clutch differences are structurally unlikely (see points 1, 4 and 6 above). We also have to be very careful about poor logic when switching back and forth from the general case to the specific case, e.g. some athletes choke, Goalie A choked in a big game, therefore Goalie A is a choker who will always choke.
Let's assume there is some small variance in clutch skill among NHL goalies. Precisely measuring that skill will be very difficult, whether you are evaluating players subjectively, objectively, or using both methods. Either way you are going to make mistakes, because chance happens and the future is unknown. If you want to be like a television broadcaster and subjectively praise players for their mental toughness and because "all they do is win", then you are going to hype some guys who simply went on a hot streak and have nothing but regression to the mean in their future. You're also going to dump on some players for their lack of fortitude who, unbeknownst to you, are going to tear up the league in future playoff seasons.
On the other hand, if you view the world the way I do, you run the risk of failing to correctly praise a player as clutch, or at least you won't do so until their careers are mostly over and they have proven that they have that ability. You will also continue to predict great things for players who have good overall records but have poor clutch performances in their early careers. Some of these players might continue to perform poorly under pressure, but many of them will see their future pressure performances improve to match their overall ability.
If someone thinks that this perspective is promoting an agenda or in some way ignoring evidence, I'd like to point out that I took the same approach on shot prevention effects. I always thought there was a small effect, but I thought it was likely fairly insignificant and I wasn't going to commit to anything at all until I had evidence of what it was.
Was I wrong to state that goalies have no effect on shots against? Absolutely, as I think there is some very good evidence that goalies can affect the number of shots against, and the observed variance among NHL goalies seems to be about 1 shot above or below average. However, there are tons of people (including Martin Brodeur himself) who are demonstrably wrong on the other side of the equation because they overestimate the effect. Guessing too high is just as wrong as guessing too low. And by doing some in-depth research on the issue from my devil's advocate position and debating others who disagreed with me, I think we've come to greater learning than we otherwise would have if I'd merely accepted the consensus opinion or came to some quick subjective estimate and left it there.
Similarly, it's highly probable that I would be wrong to state that there is absolutely no difference in clutch skill among NHL goalies. However, in the presence of uncertainty that's still the position I am generally going to take, because I don't know exactly where to draw the line and I think that most people are drawing theirs too far on the opposite side of the true marker. That makes us both wrong, but my bet is that I'm closer to being right.
It's doubtful we'll ever develop perfect metrics or track them perfectly, and even if we do there are still going to be some limitations like being constrained by sample size. In the great clutch debate, that means it is likely always going to come down to picking which error you want to make. I'd rather assume a player is not clutch and wait for proof that they are, then assume that they are and wait for proof that they aren't. I think the general correlation between regular season and playoff performance, and the observed regression to the mean of many players who at one point or another were considered playoff over- or underachievers makes my position the one that is less likely to make mistakes. I am quite aware that there will probably still be mistakes, but I'm willing to accept the trade-off. And if we can ever prove the magnitude of clutch skill for NHL goalies, then I will update my position accordingly.
Tuesday, November 24, 2009
Let Down by Goaltending?
I often point out how many overrate the importance of goaltending, and that plenty of good teams have had success with average goalies. However, that certainly does not mean bad goaltending cannot be very costly in some situations. I think there have been quite a few examples of very good teams who were dominant in the regular season but found themselves at a disadvantage when they went up against strong playoff opponents getting much better play between the pipes.
To try to identify some teams that were let down by goaltending, I looked at which teams had the best adjusted win threshold over five consecutive years without winning a Stanley Cup in that time span:
1. Boston Bruins (1974-1978) .849
2. Detroit Red Wings (1992-1996), .853
3. Boston Bruins (1980-1984), .863
4. New York Rangers (1971-1975), .864
5. St. Louis Blues (1998-2002), .865
6. Philadelphia Flyers (1976-1980), .865
7. Buffalo Sabres (1974-1978), .866
8. Ottawa Senators (2001-2006), .868
9. Calgary Flames (1990-1994), .871
10. Philadelphia Flyers (1996-2000), .871
Four of these teams won a Cup either shortly before or shortly after this particular streak, but six of them never won a single Championship despite putting together an excellent group of skaters.
Most of these teams may very well have won with a better netminder, but there are two legitimate reasons why that might not have been the case: Strength of opposition and the playoff performance of the rest of the team.
Sometimes even great teams are left playing second fiddle to an even greater team. The 1970s Bruins and 1970s Sabres teams had the misfortune of running up against the great Flyers and Habs teams of that decade. The 1980s Calgary Flames are another classic example. Despite averaging an .870 adjusted win threshold for an entire decade (1984-85 to 1993-94), the Flames won just a single Stanley Cup. I can sympathize with having to compete against a prime Wayne Gretzky, but the early '90s Flames don't have the same ready-made excuse of simply having a more powerful cross-province rival. That suggests more scrutiny needs to fall on the performance of Mike Vernon.
In other cases, it might have been the skaters that underperformed in the playoffs. For the most part, good regular season teams end up being good playoff teams, but there are some exceptions. One pretty clear example of that is the case of the Ottawa Senators. Ottawa's team save percentage actually improved from .910 in the regular season to .921 in the playoffs between 2001 and 2006. The team lost because they stopped scoring: Ottawa scored nearly a full goal per game higher in the regular season (3.27) than in the playoffs (2.29). That means Ottawa's adjusted win threshold went from an excellent .871 to a very average .905. Lalime and Emery may have had a few bad moments, but the goalies should not be the scapegoats for the Senators' spring collapses.
What do you think? Were these 10 teams let down by goaltending? Are there any other examples that did not make the list?
To try to identify some teams that were let down by goaltending, I looked at which teams had the best adjusted win threshold over five consecutive years without winning a Stanley Cup in that time span:
1. Boston Bruins (1974-1978) .849
2. Detroit Red Wings (1992-1996), .853
3. Boston Bruins (1980-1984), .863
4. New York Rangers (1971-1975), .864
5. St. Louis Blues (1998-2002), .865
6. Philadelphia Flyers (1976-1980), .865
7. Buffalo Sabres (1974-1978), .866
8. Ottawa Senators (2001-2006), .868
9. Calgary Flames (1990-1994), .871
10. Philadelphia Flyers (1996-2000), .871
Four of these teams won a Cup either shortly before or shortly after this particular streak, but six of them never won a single Championship despite putting together an excellent group of skaters.
Most of these teams may very well have won with a better netminder, but there are two legitimate reasons why that might not have been the case: Strength of opposition and the playoff performance of the rest of the team.
Sometimes even great teams are left playing second fiddle to an even greater team. The 1970s Bruins and 1970s Sabres teams had the misfortune of running up against the great Flyers and Habs teams of that decade. The 1980s Calgary Flames are another classic example. Despite averaging an .870 adjusted win threshold for an entire decade (1984-85 to 1993-94), the Flames won just a single Stanley Cup. I can sympathize with having to compete against a prime Wayne Gretzky, but the early '90s Flames don't have the same ready-made excuse of simply having a more powerful cross-province rival. That suggests more scrutiny needs to fall on the performance of Mike Vernon.
In other cases, it might have been the skaters that underperformed in the playoffs. For the most part, good regular season teams end up being good playoff teams, but there are some exceptions. One pretty clear example of that is the case of the Ottawa Senators. Ottawa's team save percentage actually improved from .910 in the regular season to .921 in the playoffs between 2001 and 2006. The team lost because they stopped scoring: Ottawa scored nearly a full goal per game higher in the regular season (3.27) than in the playoffs (2.29). That means Ottawa's adjusted win threshold went from an excellent .871 to a very average .905. Lalime and Emery may have had a few bad moments, but the goalies should not be the scapegoats for the Senators' spring collapses.
What do you think? Were these 10 teams let down by goaltending? Are there any other examples that did not make the list?
Sunday, November 15, 2009
Why Goalie Equipment Was Not Responsible for the Scoring Drop
I'm interrupting a series of posts on win thresholds to continue a discussion we had in one of the comment threads about goalie equipment. A lot of people make a big deal about the size of goalie equipment in the NHL, and the NHL is currently working on yet another attempt to "fix" this problem. Many see large goalie pads as the main reason for the low scoring rate, and feel that if more restrictions were put on equipment then the league would become significantly more high-scoring. I've seen some fans go so far as to argue that the main difference between the 1980s scoring environment and the scoring environment today is that goalies wear much larger equipment.
I think those claims are completely unfounded. The reasons for the rapid improvement in goalie numbers over the last two decades have been improved goalie technique and better defensive play. Goalie equipment size has been a minor factor.
The main proof for this is the way that the goalie crop turned over in the late '80s and early '90s. The old guys were phased out of the game, a new wave took over, and there was a rapid increase in the league-average save percentage. All of this happened before goalies started increasing the size of their equipment.
Patrick Roy is generally credited with popularizing the butterfly style. Roy played his first NHL game on February 23, 1985. At that time goalies spent most of their time on their feet, they relied on their limbs rather than their body to make saves, and they made skate saves and stacked the pads and hugged the post with their arms and did all the other traditional things goalies had been doing for years. Let's look at what happened to that group of netminders.
There were 66 goalies who played a game in that same 1984-85 season, including Roy. Their average age was 25.7 years old. Just 25 of them (38%, a little over one-third) were still in the NHL in the 1989-90 season, a mere five years later. Only 8 of those 25 were still in the NHL a decade later in the 1994-95 season. Only 2 of of those 8 performed at a high level compared to league average in the 1990s, Roy and John Vanbiesbrouck. Roy was the only one of them that won a Vezina Trophy in the 1990s, and he won his last award in 1992.
Let's fast forward a decade to that shortened 1994-95 season, and do the same analysis for that group of goalies. Remember, this is still before the equipment got huge. Here's a picture of Patrick Roy in action against the Quebec Nordiques during the 1993-94 season, for example. He has hardly any thigh-rise on his pads and his pants, chest protector and jersey all fit fairly snugly.
In 1994-95, 68 goalies played in the NHL, with an average age of 26.3. Jump ahead 5 years to 1999-00, as we did for the prior group, and we find that 44 of them are still in the league (65%, or about two-thirds). Not only that, but a dozen of them were still playing 11 years later when the league came back from the lockout for the 2005-06 season. Six out of the 9 Vezinas awarded from 2000-2009 went to goalies who were active in 1994-95, and that group included many of the top goalies of the 2000s.
Having established that the goalies from 1994-95 had much more longevity than the goalies from 1984-85, let's look at the average save percentages for those two seasons. I'll also throw in the average for 2003-04, the season with both the lowest average goals per game and the highest average save percentage of the so-called Dead Puck Era.
1984-85: .874
1994-95: .901
2003-04: .911
Power plays per game were at about the same level for all three seasons, 7.9 per game in 1984-85, 8.6 in 1994-95, and 8.3 in 2003-04. Some of the increase in save percentage would have been from defensive play, but most of it was because the goalies were better. League-wide defensive play also improved from 1994-95 to 2003-04, yet the league average save percentage only went up by .010, despite goalie equipment getting much larger. It is obvious that the more significant change happened between 1985 and 1995, not between 1995 and 2004.
We can also get a sense of the changing dynamic from 1985 to 1995 by comparing the save percentages of the goalies who were active in both periods. I chose to look at three year averages to avoid small sample sizes, including the year before and the year after for each goalie (i.e. 1984-86 and 1994-1996). There were 8 goalies in the group, but I dropped Roy since he only played 1 game in 1984-85 and therefore would really only have one season count. Roy played the modern technique anyway so his progress isn't really meaningful to what we want to track, which is how the older goalies adapted their games to a changing league.
1984-86: .886
1994-96: .900
There is a substantial improvement in the numbers. It is important to note, though, that this improvement was mostly being driven by the younger goalies in the group. The goalies who saw their numbers jump the most were Ken Wregget (.871 to .900), Tom Barrasso (.886 to .898), and especially John Vanbiesbrouck (.882 to .915), all of whom were 21 years old or younger in 1984-85. Not only were these goalies young and still not at their prime in the mid-'80s, but they already used some modern techniques or were able to adapt to the changing game.
Let's look at the older group of goalies, which includes Andy Moog, Grant Fuhr, Don Beaupre, and Kelly Hrudey. These goalies did not change their styles as much over the same period:
1984-86: .889
1994-96: .896
Despite seeing their save percentage numbers rise as a result of better defensive play in front of them, this group of four lost a ton of ground to the rest of the league during this period. They went from +.015 compared to league average in the mid-'80s to .002 below league average in the mid-'90s.
Let's compare that to the 1995 group. We want to look at the goalies who were still playing a decade later, so I picked out the 12 that played in the post-lockout NHL. I decided to compare their 1994-96 results to their numbers from 2002-04, since we want to look at seasons with no equipment restrictions.
1994-96: .907
2002-04: .911
That's just a slight increase. To be fair, we should remove Dominik Hasek, who is older than the rest of the group and is skewing the numbers with a mostly age-related decline from .926 to .914. Without the Dominator the group goes from .904 to .911, an increase of +.007. In a more defensive league with larger equipment, the increase in numbers is exactly the same as the increase we saw from the standup goalies from 1985-1995. In both cases, the league improved defensively over the period. Larger equipment would have had some small effect, but certainly not the game-changing impact that some would have you believe.
Finally, recent years have also showed us that there is not much of a relationship between equipment size and goalie play. After the lockout in 2005 there were new restrictions placed on goalie leg pads (reduced from 12" to 11") as well as glove and blocker sizes. Yet today the average save percentage in all game situations is back up to the same levels as it was in the early 2000s, despite the removal of most of the clutching and grabbing.
Just to recap, the league average save percentage went up by .037 from 1985 to 2004. Most of that improvement (.027) was already made by 1995, which was before the league-wide increase in goalie equipment size. The rest of the improvement coincided with an increasingly defensive league. When we look at the standup goalies who played in both 1985 and 1995, and compare their performance to goalies who played in both 1995 and 2006, we find that both groups increased their numbers by a similar amount even though only the latter group benefitted from huge equipment.
If I had to estimate and rank the factors that led to the change in league save percentage between 1985 and today, I would rank them in this order:
1. Improved goaltending technique (~.015-.020)
2. Improved defensive play (~.010-.015)
3. Goalie equipment size (~.005-.010)
The post-lockout crackdown on goalie equipment was still probably a good idea, but the continued focus on equipment size is in my view excessive and not something that will yield significant rewards. If the league wants to increase scoring, there are better alternatives to pursue.
I think those claims are completely unfounded. The reasons for the rapid improvement in goalie numbers over the last two decades have been improved goalie technique and better defensive play. Goalie equipment size has been a minor factor.
The main proof for this is the way that the goalie crop turned over in the late '80s and early '90s. The old guys were phased out of the game, a new wave took over, and there was a rapid increase in the league-average save percentage. All of this happened before goalies started increasing the size of their equipment.
Patrick Roy is generally credited with popularizing the butterfly style. Roy played his first NHL game on February 23, 1985. At that time goalies spent most of their time on their feet, they relied on their limbs rather than their body to make saves, and they made skate saves and stacked the pads and hugged the post with their arms and did all the other traditional things goalies had been doing for years. Let's look at what happened to that group of netminders.
There were 66 goalies who played a game in that same 1984-85 season, including Roy. Their average age was 25.7 years old. Just 25 of them (38%, a little over one-third) were still in the NHL in the 1989-90 season, a mere five years later. Only 8 of those 25 were still in the NHL a decade later in the 1994-95 season. Only 2 of of those 8 performed at a high level compared to league average in the 1990s, Roy and John Vanbiesbrouck. Roy was the only one of them that won a Vezina Trophy in the 1990s, and he won his last award in 1992.
Let's fast forward a decade to that shortened 1994-95 season, and do the same analysis for that group of goalies. Remember, this is still before the equipment got huge. Here's a picture of Patrick Roy in action against the Quebec Nordiques during the 1993-94 season, for example. He has hardly any thigh-rise on his pads and his pants, chest protector and jersey all fit fairly snugly.
In 1994-95, 68 goalies played in the NHL, with an average age of 26.3. Jump ahead 5 years to 1999-00, as we did for the prior group, and we find that 44 of them are still in the league (65%, or about two-thirds). Not only that, but a dozen of them were still playing 11 years later when the league came back from the lockout for the 2005-06 season. Six out of the 9 Vezinas awarded from 2000-2009 went to goalies who were active in 1994-95, and that group included many of the top goalies of the 2000s.
Having established that the goalies from 1994-95 had much more longevity than the goalies from 1984-85, let's look at the average save percentages for those two seasons. I'll also throw in the average for 2003-04, the season with both the lowest average goals per game and the highest average save percentage of the so-called Dead Puck Era.
1984-85: .874
1994-95: .901
2003-04: .911
Power plays per game were at about the same level for all three seasons, 7.9 per game in 1984-85, 8.6 in 1994-95, and 8.3 in 2003-04. Some of the increase in save percentage would have been from defensive play, but most of it was because the goalies were better. League-wide defensive play also improved from 1994-95 to 2003-04, yet the league average save percentage only went up by .010, despite goalie equipment getting much larger. It is obvious that the more significant change happened between 1985 and 1995, not between 1995 and 2004.
We can also get a sense of the changing dynamic from 1985 to 1995 by comparing the save percentages of the goalies who were active in both periods. I chose to look at three year averages to avoid small sample sizes, including the year before and the year after for each goalie (i.e. 1984-86 and 1994-1996). There were 8 goalies in the group, but I dropped Roy since he only played 1 game in 1984-85 and therefore would really only have one season count. Roy played the modern technique anyway so his progress isn't really meaningful to what we want to track, which is how the older goalies adapted their games to a changing league.
1984-86: .886
1994-96: .900
There is a substantial improvement in the numbers. It is important to note, though, that this improvement was mostly being driven by the younger goalies in the group. The goalies who saw their numbers jump the most were Ken Wregget (.871 to .900), Tom Barrasso (.886 to .898), and especially John Vanbiesbrouck (.882 to .915), all of whom were 21 years old or younger in 1984-85. Not only were these goalies young and still not at their prime in the mid-'80s, but they already used some modern techniques or were able to adapt to the changing game.
Let's look at the older group of goalies, which includes Andy Moog, Grant Fuhr, Don Beaupre, and Kelly Hrudey. These goalies did not change their styles as much over the same period:
1984-86: .889
1994-96: .896
Despite seeing their save percentage numbers rise as a result of better defensive play in front of them, this group of four lost a ton of ground to the rest of the league during this period. They went from +.015 compared to league average in the mid-'80s to .002 below league average in the mid-'90s.
Let's compare that to the 1995 group. We want to look at the goalies who were still playing a decade later, so I picked out the 12 that played in the post-lockout NHL. I decided to compare their 1994-96 results to their numbers from 2002-04, since we want to look at seasons with no equipment restrictions.
1994-96: .907
2002-04: .911
That's just a slight increase. To be fair, we should remove Dominik Hasek, who is older than the rest of the group and is skewing the numbers with a mostly age-related decline from .926 to .914. Without the Dominator the group goes from .904 to .911, an increase of +.007. In a more defensive league with larger equipment, the increase in numbers is exactly the same as the increase we saw from the standup goalies from 1985-1995. In both cases, the league improved defensively over the period. Larger equipment would have had some small effect, but certainly not the game-changing impact that some would have you believe.
Finally, recent years have also showed us that there is not much of a relationship between equipment size and goalie play. After the lockout in 2005 there were new restrictions placed on goalie leg pads (reduced from 12" to 11") as well as glove and blocker sizes. Yet today the average save percentage in all game situations is back up to the same levels as it was in the early 2000s, despite the removal of most of the clutching and grabbing.
Just to recap, the league average save percentage went up by .037 from 1985 to 2004. Most of that improvement (.027) was already made by 1995, which was before the league-wide increase in goalie equipment size. The rest of the improvement coincided with an increasingly defensive league. When we look at the standup goalies who played in both 1985 and 1995, and compare their performance to goalies who played in both 1995 and 2006, we find that both groups increased their numbers by a similar amount even though only the latter group benefitted from huge equipment.
If I had to estimate and rank the factors that led to the change in league save percentage between 1985 and today, I would rank them in this order:
1. Improved goaltending technique (~.015-.020)
2. Improved defensive play (~.010-.015)
3. Goalie equipment size (~.005-.010)
The post-lockout crackdown on goalie equipment was still probably a good idea, but the continued focus on equipment size is in my view excessive and not something that will yield significant rewards. If the league wants to increase scoring, there are better alternatives to pursue.
Subscribe to:
Posts (Atom)
