Thursday, April 10, 2008

Recent Form

As the playoffs begin, here is another stats breakdown, with recent form (post All-Star game stats) for the goalies on the top contenders:

WEST:
Giguere: 14-3-2, 1.61, .939, 2
Backstrom: 15-4-6, 2.06, .926, 2
Turco: 13-10-2, 2.19, .914, 2
Nabokov: 19-6-2, 2.12, .905, 1
Hasek: 10-3-1, 2.20, .901, 2

EAST:
Fleury: 10-2-1, 1.53, .947, 2
Price: 15-5-0, 2.26, .931, 3
Brodeur: 18-11-4, 2.19, .921, 0
Lundqvist: 15-6-5, 2.12, .919, 3
Huet: 15-6-1, 2.31, .918, 3

Interestingly, the Eastern goalies have done substantially better over the last few months. The Western Conference has been better this season, but it looks like the defensive play in the East, especially among the top teams, has been improving, which could indicate a competitive Stanley Cup Final series.

Tuesday, April 8, 2008

Records vs. Good Teams

As we move into the playoffs, everyone is looking for indicators of which team is likely to win. There is also a lot of discussion about goalies, as this is the time of year when goalies are most overrated in terms of their impact. Some lazy analysts just look at the starting goalies and assume that the better one will win, failing to take into account team offence, team defence, special teams, etc., which is about 75-80% of what will make up the final result.

However, one thing that is interesting to look at is to see how each team and goalie did against actual playoff opponents. For the contending teams, it is perhaps even more important to see how well they did against the other top teams. I looked at how the top teams in each conference did against the other top teams from their same conference, to try to anticipate who might be likely to go to the finals. The teams selected were Montreal, Pittsburgh, New Jersey, and the New York Rangers from the East, and Detroit, San Jose, Dallas, Anaheim and Minnesota from the West.

One might expect Brodeur and Nabokov, as the two Vezina frontrunners, to have the best numbers here. In fact, it is the complete opposite, which may not potentially bode well for their teams in the playoffs.


EAST:
Henrik Lundqvist: 15-3-2, 1.77, .926, 3
Marc-Andre Fleury: 4-4-2, 2.42, .923, 2
Carey Price: 4-1-0, 2.45, .919, 1
Martin Brodeur: 5-11-3, 2.58, .904, 1


WEST:
Dominik Hasek: 7-2-0, 1.88, .912, 2
Marty Turco: 11-6-3, 2.36, .909, 2
J.S. Giguere: 9-9-1, 2.44, .906, 1
Niklas Backstrom: 2-5-3, 2.92, .905, 0
Evgeni Nabokov: 11-8-2, 2.51, .897, 0

Wednesday, April 2, 2008

The Playoff Benchmark

In the current MVP debate, one of the most hotly debated points is whether or not Alexander Ovechkin deserves to win the MVP if his team misses the playoffs. This is quite common, to claim that someone is not really valuable unless their team wins. This is illogical, though, because Ovechkin's goalscoring dominance would be hugely beneficial to any team in the league, from Detroit to Los Angeles. The Caps are where they are in the standings mainly because of Ovechkin's teammates and coaches. If Bruce Boudreau was the coach and Cristobal Huet the goalie for the entire season, Washington would probably be the division champions even if Ovechkin only scored 40 goals. So picking Malkin or Iginla as MVP if Washington is eliminated is basically saying that Ovechkin is less valuable because his goalies and defence are worse, and where's the logic in that?

A great goalie will make more saves than an average goalie on any team. What is peculiar is that his contribution is valued much more highly on certain mediocre teams just because it made the difference between a playoff seeding and an early golf season. This, of course, has nothing to do with the goalie himself, merely the cumulative effort of his play and his teammates.

Let's say there is a goalie so good that he saves two goals per game compared to a lesser netminder. This is a vast exaggeration, as the margins between NHL goalies are very narrow and probably around a tenth of that, but it is just an illustration. Even with that overwhelming contribution, sometimes the team around him will play so poorly that they will lose even despite the extra goals he saves. Sometimes the team will be good enough that they would have won even if he never made those stops. And sometimes the goalie is the difference maker, turning a 4-3 loss into a 3-2 win.

In all three scenarios, the goalie's contribution to the team is EXACTLY THE SAME. He saved two goals for his team. The difference between winning or losing was simply in what the rest of the team added to the goalie's contribution. Therefore, it makes no sense at all to award extra bonus points when his teammates happened to play very well, or even when they were just good enough to allow him to be the difference maker. Forget "clutch" and "making the big save" and all that, the reason he lost one game and won another has nothing to do with his play and everything to do with the rest of the team in the team sport that they were playing as a team.

That is why Roberto Luongo never won in Florida (and why Tomas Vokoun isn't winning there now) because there were too many shots against and not enough goals for. On some of his best nights he may have been turning 5-2 losses into 3-2 losses, but according to the "wins are the only thing that matters" mindset he never got any credit for anything. Jose Theodore in 2002 was pretty similar, but his teammates were a little better, so he helped the Habs go from narrowly losing to narrowly winning. Different starting baseline, so therefore different result, and he ended up with the league MVP trophy. Theodore in 2002 wasn't better or more valuable than, say, Luongo in 2004, the Canadiens were just better than the Panthers.

Making the playoffs is obviously desirable, and results in additional revenues and exposure for the franchise. That doesn't mean that any effort that falls short of the playoffs is worthless, or that a player is better or worse because his team happens to be in a tight playoff race. The playoff cut line, arbitrarily drawn at 8 teams by the NHL playoff system, should not work as an irrational magnifier where all efforts are worthless up until they cross that line, at which point they become tremendously valuable.

Tomas Vokoun or Ilja Bryzgalov aren't any less valuable this year just because their teams miss the playoffs, just as Martin Gerber and Cam Ward aren't more valuable because they and their teammates might be fortunate to experience a likely very short postseason run. Vancouver could finish 8th or 9th and it wouldn't change the fact that Roberto Luongo is one of the best and most valuable goalies in the league.

So whether Washington wins or loses their next two games, vote Ovechkin for MVP.

Saturday, March 29, 2008

Most Valuable Goalie

There are many things that can be looked at in determining the greatest of all-time. Awards voting is often heavily depended on to compare players across different eras. However, especially when it comes to goalies, the awards voting is often suspect, and goalies that aren't that good but play on very good teams are often rewarded with Vezinas and First Team All-Stars ahead of probably more deserving candidates.

However, when it comes to MVP voting, this bias is less observable. There have been goalies that finished very high in MVP voting on terrible teams, the best example being Al Rollins who won the 1954 Hart Trophy on the worst team in the league. There are some who scoff at this decision, naming it one of the worst in history, but Rollins was also rated as the league's most valuable goalie in 1951 and 1953, indicating that the observers of the time thought he was very valuable to his team.

I went through the years and found which goalie ranked the highest in Hart Trophy voting, and awarded them a "most valuable goalie" award. Here are how the top goalies came out in number of times being named the most valuable goaltender in the NHL:

1. Dominik Hasek 5
2. Roy Worters 4
3. Frank Brimsek 3
3. Ken Dryden 3
3. Glenn Hall 3
3. Al Rollins 3
3. Patrick Roy 3
3. Terry Sawchuk 3
10. Martin Brodeur 2
10. Bill Durnan 2
10. Tony Esposito 2
10. Grant Fuhr 2
10. Ed Giacomin 2
10. Mike Liut 2
10. Jacques Plante 2
10. Rogie Vachon 2

These votes tended to be more spread out among various goalies, and probably gives a more realistic indicator of which goalies were dominant, rather than simply which goalies were fortunate enough to play a number of years on a dominant team.

Wednesday, February 27, 2008

The Value of Opportunity

Imagine if you worked at a profession where at the highest level there was only room for the 60 best. To get to that top level, you had to work your way through a number of different entry levels, working on a lot of different teams where you contributed in a specialized role along with one or two others possessing the same skill set. Evaluation was partly based on individual performance, but much of the grade came from the success or failure of the team as a whole. I think in this scenario it is very easy to envision a very inefficient selection process, where politics, connections, and luck all play an important role in one's eventual success.

I think we would like to believe that the NHL is an efficient market for talent, and that the best will rise to the top. However, there is plenty of reason to believe that this is not the case. It is inconceivable that there are not dozens of goalies out there who are better than Andrew Raycroft or Dan Cloutier but who are not currently collecting an NHL paycheque and likely never will.

There are two main types of opportunity or lack thereof: the opportunity to play on a contending team, and the opportunity to play big minutes. Some goalies never got a chance to play on a winning team, so they never won anything. They are often judged harshly for that reason, even though their performance might have been very, very good.

Curtis Joseph never won anything, people say, so he wasn't a great goalie and shouldn't be in the Hall of Fame. Actually, his record in the first and second rounds of the NHL playoffs is quite good (and indeed very similar to Martin Brodeur's), the difference was that Cujo's teammates just weren't as good so they lost. Joseph's record of brilliant postseason games rivals anyone of his generation, yet he is somehow seen as "unclutch". There are plenty of examples of excellent goalies who get overlooked in the annals of hockey history because their teammates were a bunch of scrubs, such as Al Rollins, Gilles Meloche, pre-lockout Roberto Luongo and others.

But at least those guys got to play in the first place. Some goalies never really caught the break to allow them to displays their talents. Jamie Storr was a very talented goalie, touted as a can't miss prospect. He had some very good stretches in the NHL as well, posting above average save percentages more often than not (from 1996 to 1999 his stat line reads: .918, .925, .929, .916). But he struggled on the few occasions when he was given the chance to win the starter's role, and never broke through as a #1. Could it be argued that he didn't have the mental makeup to be an NHL starter? Maybe. But maybe he was just unlucky that his performance happened to be relatively poor in the decisive 20 or 30 games where the window of opportunity presented itself. What if a patient, rebuilding team had given him 50-60 starts for 3 years in a row? Is it likely that his talent would have revealed itself and led to a long and successful career? You can never know for sure in what-if scenarios, but I'd make that bet.

There are plenty of what-if questions. How many goalies in the Original Six era were like Johnny Bower, just waiting for a chance to show what they could do? What if overlooked goalies like Miikka Kiprusoff had played out the string in the minors or as backups on their original teams, rather than moving elsewhere and achieving greatness? Opportunity is very valuable. If Dominik Hasek could sit around as somebody else's backup in the middle of his prime then it could happen to anybody, and when there are only 60 jobs available in the world there isn't much opportunity to go around.

Whether or not you are a fan of Martin Brodeur, it is tough to deny that he had the opportunity to enter one of the best possible goaltending situations in the game. He broke in just as scoring began to decline on what would soon become the best defensive team in the league. His team had an aging veteran (Chris Terreri) as the #1 and nobody else to really challenge for the starting job. Thus Brodeur quickly received big minutes as a starting goalie in the NHL. He had a couple of stretches early in his career where he played quite well, especially the 1995 playoffs, and became entrenched as the starting goalie in the Swamp. Over a decade of stingy team defence later, he is seen as an all-time great. Would that have been the case if he was drafted by a team with an established All-Star goalie like Belfour or Roy playing most of the minutes, or perhaps if he went to an expansion team like San Jose and faced an avalanche of rubber every night? It probably would have been quite a different story.

As the most experienced starting goalie in the NHL, with over 56,000 minutes played, it shouldn't be too surprising that by now Brodeur has become a good goalie. But how much of a role did opportunity play in his success? Probably a significant one, which is why it is interesting to speculate about how many other goalies who would have had Hall of Fame careers if they broke into the NHL in 1993-94 playing for the New Jersey Devils.

Wednesday, February 20, 2008

Subjective Factors in Goaltending

How much weight should we give to subjective factors? Can scouts really evaluate the difference between two goalies? Are public perceptions of goalies often right? Do we properly value non-save skills in goalies?

These are important questions, especially for someone like Martin Brodeur who receives more glowing hagiography about his intangibles and his goaltending artistry than anyone since Roy. A lot of the feedback I get is along the lines of, "Haven't you ever seen him play?" The problem with putting a lot of weight into these reports, however, is that these effects are almost never observed in the data, and in a number of cases seems to suggest the complete opposite.

For example, here are a few common debate points, along with the numerical reality:

Brodeur never gives the puck away (According to NHL RTSS stats, he gives the puck away more than the opposing goalie at the other end of the ice in 2005-06, 2006-07, as well as so far in 2007-08).

Brodeur prevents shots (his backup goalies have faced essentially the same shot levels as he has).

Brodeur makes shooters miss more frequently through good positioning (He has been well below average in terms of making shooters miss this year (60th among goalies) and last (45th), source: Behind the Net)

Brodeur makes the big saves at the key times (Little evidence of that, and the playoff overtime performance sample suggests, if anything, the complete opposite).

Brodeur controls his rebounds very well...this one is probably true, but it is difficult to measure and is impacted by shot quality against and defensive play in front of the goaltender.

So there are several oft-repeated refrains in support of Brodeur. Other goalies have received similar treatment - e.g. Grant Fuhr and the "big save at the key time", or Patrick Roy's ability to "carry a team on his back". Both of these claims are just as doubtful as some of the ones listed above.

I think we have to clearly separate what is aesthetically pleasing, skillful and enjoyable to watch from what actually wins hockey games. There is very little margin in goaltending to begin with. The difference between good goalies is often something like one save in 50, a difference so small it is practically unobservable by the human eye. It can then become tempting to latch onto some other factor, like perhaps puckhandling ability, past playoff performance, or some other factor to break the tie, but this results in overweighting a single skill and ignoring the larger picture since by far the most important part of a goalie's job description is of course stopping the puck.

Two of the worst puckhandling goalies I have ever seen are Patrick Roy and Dominik Hasek. Both of them were responsible for many terrible giveaways, sometimes at the worst possible moments. Yet they both stopped a much greater percentage of shots than Brodeur did, which is why at the end of the day they were both significantly better goalies. Good puckhandling goalies are fun to watch, but the evidence is that their skills don't really make much of a difference in terms of winning or losing the game.

Another issue is clutch play, and more specifically whether it exists. Studies in other sports have found evidence of clutch play to be very slight or non-existent, and that generally players perform up to their level of ability in the clutch. Good players or players that have a lot of chances to succeed with the spotlight shining on them gain reputations as being clutch, when in reality their performance at the most important times is no better than the rest of the time.

So it is difficult to reconcile the subjective viewpoints with the objective record. I probably tend to weight the measurables more highly than some, which creates a difference of opinion. I believe that a skill, to be valuable, has to have an impact on winning hockey games, and if it does have an impact on winning games then that will sooner or later show up in some kind of observable way. But the existence of discrepancies between what is observed and what is measured ensures that debates will continue to rage, especially regarding Mr. Brodeur.

Monday, January 14, 2008

Martin Brodeur and the Upside Down Career Curve

When NHL play resumed after the 2005 lockout, Martin Brodeur re-entered the fray as the two-time defending Vezina Trophy winner. However, he longer had Scott Stevens and Scott Niedermayer playing in front of him, and the new rules were supposed to open up the game and circumvent the defensive tactics executed to perfection by his Devils teammates. Many saw this to be a test of how good he actually was.

For the first three months, Brodeur failed the test. On New Year's Eve, 2005, Brodeur was lit up for 6 goals on 22 shots by the lowly Toronto Maple Leafs. At that point in the season, his stat line was a mediocre 14-14-3, 2.94, .896. Based on that small sample, it looked like those who were claiming he was a team creation had been right all along.

But whether it was a New Year's resolution, something his goalie coach spotted in his game, or perhaps some other reason, the Martin Brodeur that went between the pipes in 2006 was very different than the 2005 version.

On January 3, Brodeur made 16 saves to shut out Florida, beginning a 9 game personal win streak, 3 of them by shutout, where he posted a .934 save percentage. This was followed by a strong finish to the year, a Vezina Trophy winning season in 2006-07 where Brodeur had his highest finish in save percentage since 1996-97, and after a rocky start to the current campaign he seems to have regained his form over the last two months to appear back up on the leaderboards.

So what happened? Has Brodeur's post-lockout performance been the proof that his backers have been waiting for? Can they claim that he was unjustifiably denigrated for years because of his poor defence, based on the evidence from the last 2 1/2 seasons? This post is certainly not going to stop them from claiming that, of course, but the reality is that the Martin Brodeur of 2006-08 is not the same goalie as he was before the lockout. Since New Year's Day 2006, Brodeur's performance has improved by every goaltending measure that I am aware of.

The result is that Brodeur's career path has been the exact opposite of most goalies. Here it is, broken down into three sections:

Up to 1997-98: .915 season save %, .931 playoffs save %
1998-99 to Dec. 31/05: .909 season save %, .917 playoffs save %
Jan. 1/06 to today: .921 season save %, .919 playoffs save %

Ordinarily, goalies would be peaking somewhere during the age 26-31 range, but those were actually some of the worst seasons of Brodeur's career so far, even during some of the most successful seasons for the New Jersey Devils and when overall league scoring was very low. Brodeur has spent roughly half his career as one of the top 5-10 goalies in the league, and has spent the other half around league average, i.e. somewhere in the top 15-20, despite playing for the same consistently strong team. This is a peculiar dichotomy, and belies the common characterization of Brodeur as a "consistent goalie".

Are there any underlying factors at work here? Could it be something related to power play differential, shot quality difference, or something else related to the new NHL rules? Let's break it down further to look at even-strength and penalty kill save percentages. Overall save percentages are often skewed by how many penalties a team takes, and Brodeur's teams have nearly always been the best in the league at avoiding calls. Detailed special team save percentage data from NHL.com is only available from the 2000-01 season, but that at least allows us to compare the "dead-puck" Devils to today's version and see what has changed.

Even-Strength:
2000-01: Brodeur .919, League .916 (Leader .932)
2001-02: Brodeur .917, League .917 (Leader .934)
2002-03: Brodeur .921, League .920 (Leader .940)
2003-04: Brodeur .924, League .924 (Leader .941)

Penalty Kill:
2000-01: Brodeur .839, League .863 (Leader .902)
2001-02: Brodeur .849, League .863 (Leader .922)
2002-03: Brodeur .866, League .868 (Leader .913)
2003-04: Brodeur .878, League .868 (Leader .916)

What do we see here? We see basically a league average goalie. This despite New Jersey allowing the easiest shot quality against in the league, as calculated by Alan Ryder at Hockey Analytics. Brodeur won two Vezinas in this period, but they were certainly undeserving choices.

Moving on to the post-lockout years:

Even-Strength:
2005-06: Brodeur .922, League .916 (Leader .941)
2006-07: Brodeur .927, League .916 (Leader .933)
2007-08: Brodeur .934, League .925 (Leader .948)

Penalty Kill:
2005-06: Brodeur .869, League .863 (Leader .899)
2006-07: Brodeur .904, League .863 (Leader .921)
2007-08: Brodeur .905, League .885 (Leader .917)

Here we see significant improvement, as Brodeur outperformed the league average significantly in both categories in 2006-07, as well as so far in 2007-08. Although he has never been the league leader in any of these categories, he is certainly much closer now than he was in the early '00s. The most drastic improvement is on the penalty kill.

Here is a graph that shows the above numbers visually.



Brodeur still faces a relatively low shot total against, even post-lockout. This year he is facing 26.4 shots per 60 minutes of play, which is just two more shots per game than he did in 2003-04 when the Devils were at their trapping best. Save percentage is independent of shots faced, so that does not seem to be a factor in his improvement.

Additionally, shot quality results from Hockey Analytics and Hockey Numbers indicate that New Jersey was among the league's best in terms of shot quality against in both 2005-06 and 2006-07. It is only this season that they have fallen off. They weren't as smothering as they were at their peak under Pat Burns in 2002-04, but the system was still functioning very effectively. Many have pointed out the inexperienced defence, but recent work by hockey bloggers indicates that it is the forward group that has a larger impact on the number and quality of shots for or against, and New Jersey has some very strong two-way forwards, led by Patrik Elias and Brian Gionta.

By bucking the normal career trend by improving as he ages, as well as having multiple seasons of average play camouflaged behind an excellent defence, Brodeur is leading many to conclude that we were missing something all along, and that he was the main reason for all the wins and shutouts, not the defence in front of him. That conclusion is wrong.

Even while facing similar numbers and quality of shots as before, Brodeur is simply stopping more of them. He is better now than he was with Stevens and Niedermayer. Nevertheless, his performance over the last two seasons does not change the fact that for 6 1/2 seasons he was very average behind one of the best defensive teams of all-time. It certainly does help his career standing, and if he continues his late career resurgence for several more years he could clearly separate himself from the crowded pack of solid long-time starters from the '90's and '00's (Belfour, Joseph, etc.). Brodeur is doing an excellent late career sales job, but he is going to have to sustain, if not even increase, his current pace for a number of seasons before he can be legitimately considered even one of the top 10 goalies of all-time.