Monday, March 30, 2009

Brodeur on Rebound Control

Courtesy of frequent commenter Statman, here is an absolutely unbelievable quote from Martin Brodeur from an article by Jay Greenberg at the New York Post:

"It's nothing about style really, but about fundamentals, how I get myself in position to make the save that's important to me," Brodeur said. "We give up 8-10 fewer shots a game here than other places because of the way I control rebounds."

I know the Post is basically a tabloid, but unless Greenberg made it up that is a fascinating quote. Brodeur is implying that the Devils are the worst team in the league at shot prevention, and are being bailed out entirely by his efforts. We must also be forced to conclude that Scott Clemmensen, Kevin Weekes, and every other backup goalie the team has had during Brodeur's career also has terrific rebound control skills, because they aren't facing 8-10 fewer shots per game (in fact, after getting peppered over the weekend, Brodeur moved to within just 0.2 shots against per game of Clemmensen). By implying that his team was allowing enough dangerous shots that an NHL-calibre goalie would give up that many rebounds, and that the other team could actually get their sticks on those rebounds even if they were available, Brodeur is throwing his defence under a bus without even realizing it. For the sake of reference, a good estimate of the average number of rebound shots faced by an NHL goalie in a single game is 2 or less.

Martin Brodeur is one of the best puckhandling goalies ever, and one of the best goalies in the league at controlling rebounds, and yet he apparently isn't even in the correct order of magnitude in terms of estimating the actual effect of those things. That is something to make one think long and hard about the relative worth of subjective evaluation compared to statistical analysis.

Saturday, March 28, 2009

Quality Starts

Puck Prospectus has come up with a definition of a quality start for a goalie, and has a list of the leaders and trailers in the category for this season. Their definition of a quality start is a game with a save percentage above .912, or a save percentage between .883 and .912 while allowing 2 goals or less.

Defining and measuring quality starts is something I have hacked around a bit with, and I know others have as well. I think most quality start definitions include something to do with 2 goals or less, just because the winning percentage splits drop so dramatically for a team once that third goal goes in. The problem is that there is obviously a team element involved, stopping 14/16 is usually quite different than stopping 39/41, but save percentage is also team-influenced.

My ideal quality start would be awarded whenever a goalie allows fewer goals against than expected based on the shots he faced, but that would require a detailed shot quality analysis for every single game to determine.

Perhaps the most interesting bit in the article was pointing out that the median save percentage was .912. Last I checked the average was around .907, which shows how bad games can have a disproportionate impact on goalie stats. There isn't much difference between letting up 5 goals or 9 goals, in both cases your team is going to lose nearly all of the time, but obviously the latter figure is going to have a bigger impact on a goalie's save stats. Henrik Lundqvist is one example of a goalie who seems to have a couple of games a year where he gets shelled for 7 goals on 20 shots or something like that but is otherwise pretty consistent.

It is probably a good idea to look at metrics like quality starts to avoid penalizing goalies too much for a few bad games that really hurt their seasonal GAA and save percentage stats, or on the other hand to see if goalies that record a lot of shutouts are really putting up excellent performances from game-to-game.

Wednesday, March 25, 2009

Development Is the Key, Not Drafting

There was an interesting passage from about a month ago at From the Rink that I have been meaning to comment on:

Whatever the predicted value, Waddell has an extra draft pick to work with. The problem with that is, well, he’s Don Waddell. No player drafted by Waddell in Rounds 2-5 has yet played 150 games in the NHL. None. Nada.

The Thrashers had 25 picks in Rounds 2-5 from 1999-04. On average, that should have yielded 4.4 NHL players based on the team’s draft position(s). Colin Stuart might still make it and so might Brett Sterling and Grant Lewis but at 23 years old they are longshots.

Does anyone really believe that Don Waddell is so clueless that he picked players who were much less talented than everyone else? Or that his scouting reports were completely different than that of every other team? Even if he just was picking random players he had never seen from Central Scouting's rankings, he would have been almost certain to have at least a couple of hits if the only factor in the equation was talent. Either Waddell is actively sabotaging his team's talent acquisition by completely misevaluating players, or his team does not do a very good job transitioning its picks from being prospects to being professionals. I guess it is possible that Waddell is incompetent, but I'll play the odds here. I highly doubt that talent evaluation is the primary cause of Atlanta's poor draft record.

My philosophy is that player development is more important than drafting for non-elite prospects, e.g. everyone taken after the first 10-15 picks in the draft. The same guy drafted by Atlanta will likely have a very different career than if he was drafted by Detroit. If he goes to Detroit, he will spend several seasons at the minor league level being painstakingly developed and taught to play a strong two-way game by top-level coaches before being eased into the NHL in a limited role as part of a team with a strong winning culture in Detroit. On the other hand if he becomes a Thrasher he might get little support from a barebones development staff, get rushed to the big leagues and thrown to the wolves in tough situations on a losing team that may or may not have strong internal leadership. When he inevitably struggles through some tough stretches, the team may downgrade him as a prospect or give up on him and ship him off somewhere else. Top prospects like Heatley and Kovalchuk are likely to succeed in Atlanta, as they most likely would in any city around the league, but for a lesser player environmental factors can have a big impact on whether they succeed or fail at the highest level of professional hockey.

There are certain teams that produce NHL goalies by the bucketful (Nashville and Montreal come to mind), while others have difficulty finding a top-flight goalie. Some of this is scouting, but all scouting staffs make mistakes and miss on draft picks. Pro coaching and pro development is the missing factor that is often overlooked, but is likely to be primarily responsible for organizations being especially strong or weak at a particular position.

Tuesday, March 24, 2009

Interesting Links, and Some Thoughts on Sports Journalism

I don't usually post links to other articles, but there are a few that I wanted to highlight as they are definitely worth checking out.

First of all, JLikens at Objective NHL demonstrates that there is one more adjustment I need to make to my save percentage rankings, an adjustment for rink reporting bias. That is certainly a topic that requires future study. I don't think that an observed shot differential makes an open-and-shut case for rink reporting bias, as I think there are some teams that are more likely to allow fewer or more shots at home based on playing style, or possibly other factors like offensive/defensive strategy, commitment to matching lines, frequency of back-to-backs played on the home vs. on the road, etc. However, it is pretty clear that certain rinks do count shots differently, and that would have affected goalie numbers.

Tom Awad at Puck Prospectus did a statistical ranking of the top 10 goalies since 1944. His numbers look pretty reasonable, although I think his value over replacement metric maybe gives too much of a bonus for longevity (Tony Esposito seems a bit out of place at #4). Martin Brodeur is ranked in a tie for 5th. Interestingly enough, given the recent discussion in this space, one of the goalies tied with Brodeur is Ed Belfour.

There was an interesting quote from John Davidson that I ran across in an article by Eric Duhatschek (hat tip: Cycle Like the Sedins):

“If you take [Brodeur's] whole career playing in New Jersey and document odd-man rushes against for that whole period, he'd have the fewest odd-man rushes against, I would think – and the fewest penalties, because they're so disciplined. Style of play, him handling the puck, which means fewer injuries to defencemen, which means they're healthy to play the full season. There's a big domino effect there.”

I don't disagree with the first part, and the second part is something that would be interesting to look into.

Any of you who hate the goalie wins stat as much as I do will probably be amused by this post at Copper 'n Blue (specifically the part about Miikka Kiprusoff). The first comment is a classic, as well.

And finally, I just had to throw in a link to this article by Damien Cox entitled "Will People Really Debate Whether Martin Brodeur is the Best Ever?". Forget Awad's numbers, or mine, or anyone else's, here comes the mainstream journalist saying that in 5 years it will be completely laughable to pick anyone other than Brodeur as the best ever.

I'll never be able to match up to the excellence of Coxbloc in skewering the ramblings of the co-writer of Brodeur's autobiography, but I'd like to address this article briefly, as there has been some discussion in the comments here lately about how someone like me can reconcile the fact that I disagree with a lot of people who spend their time around the pros and are paid to cover the sport of hockey.

I don't think journalists are stupid. I have no doubt that Cox would easily be able to understand everything I have written on this blog. I don't think he lacks basic math skills, and I don't think he even distrusts statistics. I think he just forms viewpoints without defining and testing his criteria, and he is uninterested in testing those opinions by using alternate methods.

The way I see it, the best bloggers and independent hockey analysts possess two main things that are very much lacking in the majority of mainstream sports journalism:

1. Logical reasoning skills
2. Intellectual curiosity

Let's take an example from Cox's article here. He brings up talks about New Jersey's general lack of success prior to 1993-94, and then their success afterwards. Here is his argument, split into its components:

Premise 1: Lemaire became coach in 1993-94
Premise 2: Brodeur became starting goalie in 1993-94
Conclusion: "It was equal parts of Lemaire and Brodeur, then, that made the Devils develop into the type of team they became."

They both showed up at the same time, therefore they are equally responsible? That quite clearly does not follow, and no attempt was made to quantify or even reasonably subjectively evaluate the relative contributions of each, much less the other 19 skaters on the roster. Something happened, and somebody was there while it happened - well, he must have contributed to it. Martin Brodeur's team won the Stanley Cup in 2003 while Roberto Luongo's team missed the playoffs. I guess that means Brodeur must have been the better goalie. Grant Fuhr has won a lot of championships, he must have been clutch, and so on.

Cox's whole article is a great example of a lack of clear logical argument. It is, however, a typical journalist's greatest ever article, a hodge-podge of observations, anecdotes and opinions that are somehow supposed to coalesce into a coherent demonstration of greatness. It is distinguished by its lack of an attempt to compare the subject to others, even peers who played at the exact same time Brodeur did, and its lack of defining the relevant criteria of greatness. Does Cox consider puckhandling skill to be more or less important than playoff success? How about "defining the personality of a franchise", is that more or less important than Vezina Trophies? Who knows?

Not surprisingly whenever a journalist sits down and types a bunch of unrelated items into his computer and calls it a proof, the article tends to fall a bit flat. Even more so when, as in this instance, the opinion espoused happens to be wrong in the first place.

Point 2, lack of intellectual curiosity, tends to come up when people bring numbers to the table. Fire Joe Morgan was classic at exposing mainstream journalists who would ridicule advanced statistical metrics because they disagreed with them, without even understanding what they meant.

That kind of anti-numbers bias comes up in hockey as well, but there is more to it than that. To me, journalists seem to be satisfied with simple explanations, and seem to have little interest to investigate further to see whether something is true. I have read the attempts of a number of different journalists to account for the effect of New Jersey's excellent defensive play on Brodeur's success, and I've never seen any of them talk about shot quality. They'll usually pull up some carefully selected irrelevant metric to show that it doesn't matter (e.g. "Brodeur ranked in the top 10 in shots against seven times in the last 10 seasons"), or they'll gloss it over by talking about at best tangentially related things like New Jersey's offensive performance or the number of Devils coaching changes, or they'll demonstrate that New Jersey did not have excellent defensive personnel or excellent shot prevention in 2007-08 and skillfully extrapolate those results backward over the prior 14 years of Brodeur's career.

The reason I focus on Brodeur so borderline obsessively is that I find his career to be very interesting. He has had spent almost his entire career within an extreme team context, and he has a large gap between the subjective evaluation of hockey observers and the objective evaluation of the statistical record. He played behind a great defence - how much does that help a goalie? He played a lot of games - how hard is that to do, and how valuable is it to a team? He is great at all the goalie non-save skills - how big of an impact does that have on the rest of his team? His team won a lot of games and Cups - was that because of great/clutch goaltending, or because of superior team play?

Answer all of those questions for Brodeur and you can pretty much do it for anyone, and therein lies the challenge. But getting a complete answer to any individual one of them is not easy, much less properly evaluating the whole, and that is why you can forgive me if I don't have a ton of respect for journalists who haven't even attempted any of that legwork trying to tell me the case is already closed.

Monday, March 23, 2009

Belfour's Shot Prevention

When some goalies are in the net, fewer shots are taken by the other team. Although I was once skeptical of this effect, it has been shown to be pretty clear in the historical data. Martin Brodeur is a goalie who usually gets a lot of credit for his puckhandling and other skills that likely contribute to a reduced shots against total. There are, however, other goalies who are also very good at those skills.

I believe the goalie who might be the most overlooked in this aspect of goaltending is Ed Belfour. Having closely compared their shots against records, there is good evidence to suggest that Belfour's shot prevention effect may be every bit as large as Martin Brodeur's.

Belfour is a little easier to evaluate since he averaged fewer games per season and played on a number of different teams during his career. To do my comparative shots analysis, I usually look for goalies that had both substantial playing time with the study goalie as well as lots of minutes played on other teams. There are three goalies that fit these criteria that we can use to evaluate Belfour: Jeff Hackett, Roman Turek, and Marty Turco.

In this type of analysis, I prefer to take the average of yearly averages rather than simply calculate an average from the totals, because otherwise it skews the data when there are seasons with much higher or lower minutes played totals. Belfour played with Hackett from 1993-94 to 1996-97, and averaged 27.3 SA/60 per season, compared to 29.2 SA/60 for Hackett. That is a gap of about 2 shots per game. Over the rest of his career, Hackett tended to face more shots than his teammates, averaging about one extra shot per game against. That gives us an estimate for Belfour of about one shot per game saved.

Belfour played two seasons with Roman Turek in Dallas, and faced 0.5 fewer shots per game. Turek was pretty consistently about a half shot below his goalie teammates throughout the rest of his career, which again supports the one shot per game number.

In his two seasons playing with Marty Turco, Belfour was about a shot per game better than Turco, which is impressive since Turco has been half a shot per game better than his backups over the last few years (and Dallas has tended to bring in goalies who play a similar style, so Turco's effect might even greater when you consider he is being compared to guys like Johan Hedberg or Mike Smith). It could be that Turco had not yet developed his skills to the same extent early in his career, or that he learned a thing or two from Belfour that he was able to apply later on, or maybe there were some other variables that were influencing the shot numbers.

The results from all three goalies suggest that Belfour has a shots against effect of at least one shot per game. I did another piece of work where I compared how the backup goalies did while playing with a specific goalie and how they did on other teams. Ed Belfour faced 26.7 shots per game, compared to 27.9 for his backups. His backups had a weighted average of 28.4 on other teams, which suggests that although his defences were better than average at preventing shots, Belfour contributed to his team's shot prevention.

For the sake of comparison, Brodeur faced 25.4 shots per game compared to 26.1 for his backups, who had a weighted average of 28.5 shots per game on other teams. This shows that New Jersey had a significant defensive effect. Subtracting the differences between the two of them, and you get a 1.2 shot differential for Belfour and a 0.7 difference for Brodeur. It is likely that weaker competition and other small sample size factors mean that Brodeur's figure is a bit understated, and those numbers do not include the 2008-09 season where Brodeur has so far faced about 2 fewer shots per game than his teammates. Still, it is more evidence that Belfour is comparable to Brodeur in terms of non-save skills.

I am willing for now to credit both Belfour and Brodeur with preventing 1 shot per game compared to average goalies. I also think that this information is the decisive factor that separates them both from other goalies like Joseph and Vanbiesbrouck who have similar save percentage records.

It does appear that the Brodeur vs. Belfour debate is a lot closer than most people would think. If these estimates are correct, then Brodeur doesn't gain an advantage over Belfour in terms of non-save skills, and the comparison between them should be decided by puckstopping ability alone. Brodeur has a better save percentage record compared to league average, but evidence suggests he also faced easier shots, since Belfour spent some of his career on bad teams (Florida, San Jose) and other parts of his career on teams that likely allowed shots of a higher-than-average difficulty (e.g. Toronto). If you compare Belfour's Dallas numbers to Brodeur's New Jersey numbers at the same time, which were likely two fairly similar team contexts to play in, their stats are essentially identical: 2.18 GAA and .909 save % for Brodeur vs. 2.19 GAA and .910 save % for Belfour.

I think that both have had pretty similar careers - they had some great individual seasons early, had lots of playoff and team success as members of terrific two-way defensive teams, and then spent a few seasons on weaker teams yet still performed pretty well. They also had some off-years mixed in, although New Jersey's defence did a better job of camouflaging Brodeur's down seasons compared to Belfour, who actually lost his starting job twice - to Hackett in Chicago and to Turco in Dallas.

The main reason that I think there is a reasonable case for Belfour over Brodeur right now is playoff performance, where in my estimation Belfour has been pretty clearly the better goalie. If my shot quality estimates in my last post were correct, then their regular season records might actually be pretty similar as well. Having said that, however, I think I would still take Brodeur's career over Belfour's right now, and with a few years left Brodeur will likely leave little doubt before his career is over.

Monday, March 16, 2009

Brodeur, Roy and Hasek: The Debate Rages On

With Martin Brodeur having tied Patrick Roy's wins record, there is a lot of debate going on about who was better and who is the greatest goalie of all-time. Everyone else is doing it, so I might as well join in. I've done similar things before, but I've got a couple of new wrinkles this time.

The typical debate is set up as a choice between having 4 Cups and 3 Conn Smythes vs. having the career wins and shutouts record. I think all of those things are strongly team dependent and are correspondingly overhyped, so I'm not even going to bring them up. Having done a lot of research lately into shots against by goaltender, I have come up with some estimates of shot prevention effects, and would like to use those numbers to review the save percentage vs. league average results I posted some time ago.

I prefer to rank goalies by taking their save percentages and adjusting for all the important factors. Therefore, I have included a shot prevention adjustment (by giving goalies credit for shots they likely prevented and subtracting from the goalie's shot total for shots they likely had a hand in creating; if you haven't read any of my work on the topic check out this post estimating the effect for Brodeur) and a team defence adjustment based on the quality of scoring chances against, which gives an adjusted save percentage that can be compared against league average to account for differences in league scoring levels. I also ran the numbers for a few others (Belfour, Joseph, and Luongo) who should also be in the conversation about the best goalies in recent years.

These adjustments were mainly derived by comparing performance by backup goalies while on the same team to their performance on different teams, and using that that to assess the overall team context. There are many variables still in play in that type of comparison, such as quality of backups, quality of teams, small seasonal sample sizes, and the usual year-to-year random fluctuations, so I mostly took what the numbers said but did make a few subjective adjustments. They included adjusting downward the shot quality numbers for Roy and Brodeur, who both had results that were far overstated because their backups played a lot of games on bad teams in other cities, and increasing Brodeur's shot prevention effect and lowering Luongo's based on a more detailed comparative analysis of their performance relative to their teammates.

Here are my estimates:

Patrick Roy: 2.5% easier shot quality, 1 shot created/gm
Martin Brodeur: 5% easier shot quality, 1 shot prevented/gm
Dominik Hasek: 2.5% harder shot quality, 0.5 shots created/gm
Roberto Luongo: 0% harder shot quality, 1 shot created/gm
Ed Belfour: 0% harder shot quality, 1 shot prevented/gm
Curtis Joseph: 2.5% harder shot quality, 0.75 shots created/gm

That leads us to the following results:

GoalieSave %SA/60GAASA PrevAdj SASA AdjS%SQ AdjS%

These numbers allow us to compare the adjusted save pecentages to league average and calculate a number of goals above average for each goalie that combines quantity and quality:

RankGoalieAdjSV%LgAvg% DiffSAGOA

After letting some of the air out of Roy's numbers, Dominik Hasek reigns supreme at the top of the rankings list. The surprising result is how close to the rest of the pack Patrick Roy ends up, although these numbers are from the regular season only.

Ed Belfour's ranking is also a point of interest. I think nearly everyone would rank him 4th out of this group but well behind the top 3. That's probably underrating Belfour. I have long thought that there was much more of a gap between Hasek and Brodeur than between Brodeur and Belfour, and these numbers certainly support that.

I ran the numbers for the playoffs as well, but without the same ability to compare backup results those numbers are entirely based on guesswork. I'm sure the shot quality factors were different, since the opposition is tougher and the number of games played on each team in the regular season is different than the number of games for each team in the playoffs. Belfour likely faced easier shots in the playoffs because of all the deep playoff runs he had in Dallas, and Roy's difficulty probably rose because of strength of competition and more games played in Colorado. This is an imprecise measure to be sure, but I'd guesstimate the playoff goals above average numbers as something like the following:

1. Patrick Roy, 74.6
2. Ed Belfour, 51.8
3. Dominik Hasek, 31.3
4. Martin Brodeur, 24.3
5. Curtis Joseph, 22.3
6. Roberto Luongo, 8.1

Obviously the inputs determine the results in a study like this, so there can and should be considerable debate about the adjustments I've made. I am not claiming to have ironclad proof on any of them and I am open to the possibility of any or all of them being wrong. The most discussion-worthy adjustments, and possibly the most difficult ones to estimate, are the strength of team defensive adjustments for Patrick Roy and Martin Brodeur. I think it is pretty clear both goalies benefitted from their teams, but the question is how much.

I think Roy's context is probably a little tougher to evaluate. Playing for Montreal in the 1980s was probably relatively similar to playing in New Jersey in the 1990s, with great team defence and fewer than average power plays by the other team. Then Roy was traded to Colorado, who had a different style of play. The shot quality data we do have available from '03 and '04 indicates that New Jersey was much better than Colorado at preventing opposing scoring chances, which is primarily why I gave Roy a different overall shot quality rating than Brodeur.

Overall, I think it is pretty clear that Dominik Hasek is the best goalie of the last 20 years (and I would argue the best goalie ever). As far as Brodeur vs. Roy goes I'd still take Roy. I think Roy's peak is well ahead of Brodeur's (illustrated graphically here), and Roy has also been better in the playoffs, but it does seem like the more work I do on St. Patrick the more question marks are raised about how much of his success was from team factors.

If Brodeur keeps up his current level of play for several more seasons (the previous three seasons account for over one-third of Brodeur's career goals over average total), then he will be at least moving into the conversation with Roy. If we are able to more precisely drill down to the relative team effects and adjust for them maybe we'll find that the team factors between the two aren't that different after all, and in that case the debate could get very interesting by the time Brodeur's career is done.

Friday, March 13, 2009

Special Teams and GAA

What would you rather do, play 4 minutes at even-strength, or get a 2 minute power play followed by a 2 minute penalty kill? If you had a normal team that didn't have an unusually dominant power play or penalty kill, then it likely wouldn't matter much in terms of winning or losing the game since you would not gain an advantage over the opposition in either scenario. If you are the goalie, though, you'd much rather play 5 on 5, because it means a lower chance of getting scored on.

Based on the numbers this season at Behind the Net, an average team that played all 60 minutes at even-strength would score about 2.4 goals per game. An average team that played 30 minutes on the power play and 30 minutes on the penalty kill would score about 3.7 goals per game, or about 50% more often. The scoring rate on the power play is roughly triple the even strength rate. The overall shots are likely to be fairly similar in both scenarios, the difference is that power play shots are much more likely to go in. Save percentages on the penalty kill usually hover around .870 or so, while the average save percentage at even-strength is up around .920.

Some teams appear to be more low-scoring than they actually are because they don't spend much time on the power play. The New Jersey Devils have been an example of this type of team, and another is the Minnesota Wild. The opposite is true for often-penalized teams like the Anaheim Ducks and the Philadelphia Flyers. A team that wants to improve its goals against without bringing in extra defensive talent can simply coach its players to take fewer penalties.

Teams that take few penalties tend to also draw fewer penalties, but a team that was terrific at drawing penalties while being also disciplined enough to avoid taking penalties would have a big advantage. That description fits this year's Carolina Hurricanes, who lead the league in power play opportunities for while also having faced the 5th fewest power play opportunities against. The Hurricanes special team units are pretty mediocre (Carolina has the 21st ranked power play and the 18th ranked penalty kill), so they haven't really taken advantage of this as much as they could have, but the team is still +4 in goal differential on special teams compared to -5 playing 5 on 5. If the Hurricanes had been exactly average in taking and drawing penalties, they would be expected to score 48 power play goals and allow 55, so the net result of their team discipline is +11 goals.

Combine team discipline with a weak division and some good play/luck in close games (the 'Canes are 19-7-6 this year in games decided by one goal), and you have a team that is in the playoff hunt. This just illustrates the potential impact and importance of penalties in today's NHL.

Sunday, March 8, 2009

GMs vs. Media

There is often a great deal of similarity between voting for the Vezina Trophy, which is done by the league's general managers, and the voting for the year-end First and Second All-Star Teams done by the broadcast media. Last year was an example of a time when they did not agree, however, with Brodeur winning the Vezina and Nabokov getting named to the First All-Star Team. I thought it might be interesting to highlight some of the goalies who have had different results in Vezina and All-Star voting, not in terms of any particular season as in the case of Nabokov and Brodeur, but over the course of their careers to see if there was anyone that the GMs thought highly of but was overlooked by the writers.

Award voting is difficult to compare directly, since the number of voters changes from year to year. The best method is probably the one used at, where the voting share is calculated for each goalie by dividing the number of voting points by the number of points a goalie would receive if he was a unanimous winner. That gives us a single scale that allows us to not only compare from year-to-year, but also between Vezina and All-Star voting. To get a career total, you just need to add up the total award "shares" for each goalie. For example, if a goalie gets 100 points out of a possible 200, that is a 0.50 share. If he has a 0.25 share the next season, and a 0.10 share the season after, his career total is 0.85.

For the well-known goalies there isn't too much difference between the two totals. Here are the results for the 4 most likely recent Hall of Famers, who all have All-Star voting totals between 8-15% higher than their Vezina results:

Belfour: 2.49 Vezina, 2.86 All-Star
Brodeur: 5.19 Vezina, 5.75 All-Star
Hasek: 4.76 Vezina, 5.22 All-Star
Roy: 4.64 Vezina, 5.00 All-Star

It is fairly standard for the well-known goalies that All-Star voting surpasses Vezina voting, since there tends to be more consensus. There are more a lot more writers voting on the awards than GMs, so one or two off-the-wall picks have less of an impact percentage-wise. The writers are also probably at least somewhat aware of each other's articles and published opinions, so that will influence some groupthink. It is also likely that some writers simply don't have a good idea of who the best goalie is, so they pick the most recognizable name.

On the other hand, some GMs don't get to see all the teams play so they may focus primarily on their own conference or division, or might even just throw some support behind their own goalie, which leads to more spread out voting results.

There were a number of goalies that accumulated substantially more Vezina shares than All-Star voting shares, meaning that they were valued higher by general managers than the media. If we assume that general managers have extra inside information from professional scouts as well as their hockey experience and expertise in evaluating talent, we would expect that the GMs should make better picks, and that the goalies that come up on this list should be goalies that are considered underrated.

There were 5 guys who met my threshhold of having Vezina shares that were at least 20% higher than All-Star shares:

Kelly Hrudey: 0.38 Vezina, 0.12 All-Star
Guy Hebert: 0.14 Vezina, 0.02 All-Star
Curtis Joseph: 1.02 Vezina, 0.42 All-Star
Daren Puppa: 0.82 Vezina, 0.60 All-Star
John Vanbiesbrouck: 1.52 Vezina, 1.07 All-Star

I have been less than flattering in some of the things I have written about Vezina voting and general managers, but here I'm going to be quite complimentary. That is a pretty good list.

Kelly Hrudey, Guy Hebert, and Daren Puppa are all guys that have pretty solid save percentage records, and often pop up in unexpected places when I look at various statistical comparisons. Curtis Joseph and John Vanbiesbrouck both have very good save percentage record compared to their peers in both the regular season and playoffs, but never had the team success that attracts recognition.

Curtis Joseph is the goalie who was most consistently rated higher by people inside the game of hockey than by casual observers. In the eyes of many fans, Curtis Joseph is a loser who always choked past the second round of the playoffs and never accomplished anything. Many people consider him to be a borderline Hall of Famer, despite being 4th all-time in the career wins list. Joseph never won a Vezina or was named a First or Second Team All-Star, and he never played in a Stanley Cup Final. However, if you look at insider perspectives on his play, including Vezina voting, he was repeatedly rated among the very best in the game.

Joseph did not have a single season in his career where his All-Star voting share was higher than his Vezina voting share. The GMs always rated him higher than the writers did, and the most extreme example was during the 1998-99 season, when Joseph was the Vezina runner-up and actually received more first-place Vezina votes than eventual winner Dominik Hasek (!), yet finished just 4th in All-Star voting. Joseph was picked to play on Team Canada for three consecutive best-on-best tournaments, and began the tournament as the starter in two of them, despite playing in an era of strong goalie competition. Joseph was always a highly sought after free-agent and inked a series of lucrative deals, including signing for $8 million per year with Detroit in 2002 (the same amount the Red Wings were paying Hasek). Joseph was voted team MVP several times in both Edmonton and Toronto, and according to one source I found he was apparently a Lester B. Pearson finalist in 1998-99, which suggests that the other players around the league seemed to agree.

As I have argued many times before, NHL general managers are not always great at picking the best goalie in any given season, as they can be blinded by wins and shutouts like anyone else. However, the record shows that they are better than the writers at identifying overlooked goalies and rewarding goalies who play on weaker teams.

Ottawa Scoring

I looked up some stats to show the decline in Ottawa's scoring before and after January 1, 2008, to support my claim that is was primarily a decline in offence that caused their tumble in the standings over the last season and a half. Here are points per game stats for the key players on Ottawa:

Dany Heatley: 1.31 before, 0.93 after
Daniel Alfredsson: 1.21 before, 1.02 after
Jason Spezza: 1.37 before, 0.89 after
Mike Fisher: 0.71 before, 0.46 after
Chris Kelly: 0.47 before, 0.31 after
Wade Redden: 0.53 before, 0.33 after
Chris Phillips: 0.31 before, 0.21 after
Anton Volchenkov: 0.23 before, 0.17 after
Other top 4 defencemen: 0.45 before, 0.34 after
All other forwards: 0.32 before, 0.26 after

There was only one key player on Ottawa who had a scoring rate that improved since January 1, 2008. He went from 0.54 points per game to 0.56 points per game. What was his reward for reversing the trend? Getting traded for Columbus' backup goalie. My sympathies to Sens fans, because the future doesn't look particularly bright in Ottawa.

Friday, March 6, 2009

Brodeur Is No Fraud

Mike Brodeur, that is. The Rochester Americans goalie and Florida Panthers prospect is currently 3rd in the AHL in save percentage, and is having a great season that earned him an invite to the AHL All-Star Game.

He has also already accomplished one thing that Martin Brodeur has never been able to do: Massively outplay his teammates. Check out these stats:

Mike Brodeur: 16-7-3, 2.29, .926
Other goalies: 8-26-2, 3.75, .886

Don't think those other goalies are slouches, either, most of the other games were played by former NHLer Chris Beckford-Tseu (OK, so he played 27 minutes, but he still made it to the show) and 2005 2nd round pick Tyler Plante.

The director of player personnel for the Panthers has been quoted as saying, "This guy is legitimately a prospect for the NHL", so that's good news for Mike. Florida has Vokoun and Anderson both playing well, and top prospect Jacob Markstrom on the way, which will make the path a bit more difficult for the lesser Brodeur but if he keeps up his pace he might just earn an NHL shot.

We wish Mike the best of luck as we have nothing at all against Brodeurs. Martin is a nice guy by pretty much all accounts, except for possibly those of his former in-laws, and Richard had a few decent years as well. We just take issue when people undeservedly call them the greatest of all-time. That is something Mike Brodeur probably doesn't need to worry too much about.

Thursday, March 5, 2009

Hey Ottawa: Blame the Scoring, Not the Goalie

I don't know why the Ottawa Senators continue to think that their problem is goaltending. Trading Antoine Vermette for Pascal Leclaire and a 2nd round pick is an odd move.

As everyone knows, the Ottawa Senators fell off a cliff somewhere around January 1, 2008. I'm not sure I've ever seen such a dramatic change on a team - if you compare their win/loss record and goal differential before and after New Year's last year, the difference was about the equivalent of this year's Detroit Red Wings turning overnight into the Phoenix Coyotes. In their last 105 games, Ottawa has scored 277 goals and allowed 319, for a goal differential of -42.

The average Eastern Conference team has scored 307 goals and allowed 311 over the same span, meaning that the Sens are slightly worse than average in goal prevention but well below average in goal scoring. Ottawa does need to improve its defensive play, but the big problem seems to be the complete lack of secondary scoring, something that is going to be even worse now without Vermette, the team's highest-scoring second liner both this year and last year.

The Sens' team save percentages over the last 3 years have been .914, .904, and .906. Shot quality numbers have indicated the Sens have allowed slightly more difficult chances than average over that span, which would put the Sens' goaltending around league average. Over the last two seasons, playing on a Ken Hitchcock coached team, Pascal Leclaire has posted a .909. I don't see Leclaire as much of an upgrade over Auld, and why would a team that is going to miss the playoffs anyway not want to give Brian Elliott as much experience as possible?

If you have a team with a well below average offence and OK goaltending, then logic suggests that it might not be the most necessary move to trade your highest-scoring second liner for another team's backup goalie (who only has one good season behind a strong defensive unit to his credit, no less). I give Columbus the clear upper hand in this transaction.

Wednesday, March 4, 2009

Chart of the Day

The following graph is of the difference between save percentage and league average for Patrick Roy (blue), Dominik Hasek (green), and Martin Brodeur (red). Since goaltending results are often highly variable from year-to-year, I smoothed the curves by averaging the season together with the one before and the one after, i.e. three-year rolling averages. I believe I once referred to Brodeur as having an "upside-down career curve", and this lays that out pretty well.

Brodeur's abnormal career path makes it difficult to project what kind of a decline he will see as he ages. He is already defying the standard projections on aging (check out this post at Mc79hockey from three years ago that outlines how Brodeur should have performed over the last few seasons based on typical averages), and has now come back from a 4 month injury break apparently without missing a beat. I think the observed results suggest that Brodeur is not going to decline in a typical fashion, and he may very well be able to keep up his current level of play for several more seasons.

There are many New Jersey fans that lament Brodeur's lost season during the lockout, as he would otherwise already be the all-time wins and shutouts leader. However, looking at this graph one has to wonder whether taking that time off was possibly a good thing for a guy who played both more regular season and more playoff games than everyone else in the preceding decade. I doubt we will ever know for sure, although there is a lot of research that can be done on the relationship between the rate of decline from injuries and aging and the games played and shots faced by a goalie.

Tuesday, March 3, 2009

Jacques Lemaire Gets You Paid

The Minnesota Wild signed Niklas Backstrom to a 4 year, $24 million contract. I first saw the news on James Mirtle's site, and I'd say he does a pretty good job outlining the reasons why Minnesota should have ushered in the Josh Harding era, if you aren't familiar with them already.

If I was GM in Minnesota, I would trade my goalies in the last year of their contracts, if anyone was willing to bite. If not, I would kick every last one of them out the door rather than pay for their inflated numbers.

Having said that, Backstrom is a decent goalie and Minnesota should be fine with him for the next four years. It just doesn't make sense in a salary capped league, while facing economic uncertainties that may lower the cap in future years, to pay a lot of money for good but not elite goaltending if you have a terrific defensive team already. Minnesota has had an exellent save percentage for years, and they haven't managed to make the leap to the upper echelon of teams in the NHL. It's going to be even harder now with less money to spend on the guys up front. The Wild would be much better off finding and signing the next Marian Gaborik to upgrade their 26th-ranked offence than overpaying Niklas Backstrom.

Monday, March 2, 2009

Shots Against Effects

I thought of another way to break down shots against and save percentage - by looking at goalies with similar league rankings from year-to-year to see if goalies who faced fewer than average or higher than average shots were likely to have a save percentage that differed from the norm. Even if there is no relationship in an overall sense, there could still be some relationship for goalies with extreme shots against results, whether high or low. After all, when we are comparing say Turco in Dallas to Vokoun in Florida, we are talking about the opposite ends of the spectrum in terms of team prevention.

I took a sample of the top 40 goalies in minutes played for each season from 2000-01 to 2008-09, and then looked at the save percentage stats and rank for all the goalies who ranked #1, #5, #10, #15, #20, #25, #30, #35, and #40 in shots against per 60 minutes each season, where #1 was the fewest and #40 was the most.

Here is the breakdown:

1st in SA: .908 save %, avg rank 21
5th in SA: .908 save %, avg rank 24
10th in SA: .909 save %, avg rank 21
15th in SA: .903 save %, avg rank 27
20th in SA: .898 save %, avg rank 30
25th in SA: .911 save %, avg rank 17
30th in SA: .909 save %, avg rank 19
35th in SA: .915 save %, avg rank 13
40th in SA: .916 save %, avg rank 13

Those results are pretty consistent across the board. The only ones that are really striking are the low results for #15 and #20, which wouldn't be expected by any commonly advanced shots against theory, and the high results for #35 and #40, which could potentially indicate an advantage to facing higher shots against totals.

The most obvious factor that can be influencing this analysis is goalie quality. Since any goalie can finish in any one of these spots, one grouping could be Brodeur, Roy, Belfour and Hasek while the next could be Cloutier, Raycroft, Esche and Kidd. The actual groupings weren't that extreme, but goalie quality does explain the weird results for the goalies who ranked 20th, as Vernon, Turek, Grahame, Conklin, Khabibulin, Tellqvist, Ward and Toskala was easily the weakest group of goalies. The goalies who ranked 15th weren't much better (Thibault, Roy, Storr, Weekes, post-lockout Theodore, Ward, Lalime, Price this year). It appears to be just a fluke of a fairly small sample size that those two ranks attracted lesser talent and led to lower save percentages. On the other hand, both the 35th ranked and 40th ranked goalie groups were strong, with goalies like Burke, pre-lockout Theodore, Roloson, Huet, Lehtonen, and Luongo three times, along with a few lesser lights in Rhodes, Hnilicka, Denis, Hedberg, Anderson and Chris Mason.

Here are the numbers adjusted for the average career save percentage for each goalie in the sample and normalized to the league average of .907. This works pretty well for most of the goalies, with the exception of those who have played just 1 or 2 seasons, like Carey Price, or goalies whose careers began in the 1980s, like Patrick Roy.

#1: .901
#5: .910
#10: .911
#15: .903
#20: .902
#25: .908
#30: .911
#35: .914
#40: .913

This list makes it look like it was very difficult to face the fewest shots in the league, but that is not really the case. The adjustment is somewhat misleading, as the average career save percentage is overstating the strength of the group. Dominik Hasek faced the fewest shots against in the league in both 2006-07 and 2007-08, so his .922 career mark is counted twice by this method although he was well past his prime in those two seasons. This year, current fewest shots against leader Steve Mason counts as .920, since as a rookie this season is all we have to go on. Mason may be a good young goalie, but he is unlikely to sustain that mark over an entire career. If we replace these adjustments with average values, then the #1 group improves to a .908 adjusted save percentage, only slightly lower than the others.

The two highest-shot groups finish 1-2 in the adjusted rankings as well, which does seem to indicate that there may be some advantage at work. However, the main reason for these excellent results are that they included the two best high-workload, high-save percentage seasons in the period (Jose Theodore in 2001-02 and Roberto Luongo in 2003-04). Remove those two years, and both groups end up with an adjusted save percentage of .911, which is in line with everything else.

There might be a slight save percentage advantage to facing high shot totals and possibly even a slight disadvantage to facing low shot totals, but it is probably at most a couple thousandths. Otherwise, over an 8 season sample it did not appear to make much difference at all whether goalies faced fewer shots than average or more shots than average. The results were certainly within the margin of error given the sample size, or could be explained by differences in goalie quality. The evidence continues to mount that there appears to be no significant relationship between save percentage and shots against.