Friday, February 27, 2009

A week of Puck Prospectus

I was quite interested to see the launch of Puck Prospectus, Baseball Prospectus' entry into hockey analysis. While there are lots of people doing hockey analysis, both inside the NHL and on their own, conventional hockey reporting has yet to absorb any of it, not even to the point where hockey columnists need to dismiss its practitioners as "a bunch of guys sitting in their mom's basements."

At any rate, I thought I'd give a brief run-down of Puck Prospectus' first week of articles:

Robert Vollman: Projecting Future Scoring. Similarity scores are a great way to predict a player's future performance, particularly in baseball, where a multitude of statistics and positions can give you a sense of what kind of player someone is. There are things you can suss out about a player's likely aging curve (eg: Ben Grieve, young players with old players' skills) that you would miss with a generalized aging curve. But using just hockey boxcar stats? I think there's not enough information there - I'm guessing that a simple "projection" system like Tangotiger's Marcels would do just as well. Hopefully Rob can give us more details and show us a better system.

Iain Fyffe: The Beginning. I like this approach: since so many readers are essentially uninitiated in hockey analysis, explain the basics. The most important thing you look for in a future NHL star is high point totals at a young age. And of course if you're comparing players to one another, you need to make an allowance for offensive variations over the years.

Timo Seppa: Plus/Minus - A Nonsense Stat?. This article compares Plus/Minus to RBIs, and, after showing the context-sensitive nature of +/-, dismisses it as a nonsense stat, like RBIs. Unfortunately, there's a big difference between RBIs and +/-: because run-scoring in baseball can be separated into context-independent components (singles, doubles, triples, home runs, walks, stolen bases, etc...), RBIs never come into play in advanced statistics. But a player's value in hockey is, in essence, captured by the number of goals he contributes to, minus the number he allows. There are obviously adjustments to be made for linemates, opponents, defensive zone faceoffs and the like, but at the most fundamental level, a player's plus/minus is his value to his team. In other words, it's very much not nonsense.

Tom Awad: Bayesian Power Rankings. This is a great way of looking at the NHL. You can see, for example, that the Leafs somehow have a 9% chance of making the playoffs! Since this is all done at a team level, one thing that's hard to assess is a team's real winning percentage - you have to assume that they are exactly as good as they have been. Compare that to baseball, where individual projections and lineup predictions can be used to estimate the inherent quality of a team and possibly get a better sense of how they'll do going forward, particularly at the beginning of the season. It probably takes one person's spare time to do this for the NHL, so maybe that's what Puck Prospectus has in store for us in the long run.

Andrew Rothstein: Second Half of February Trades. I'll admit I'm a little confused by the discussion in this piece. Andrew refers to several things that I'm not familiar with: Even-Strength Shooting Percentage Differential, a 1-point-per-game barrier for rookies, Special Teams Pythagorean winning percentage. BP has most of their jargon linked and defined - PP might be well-served to do the same, and to spend a number of articles outlining their methodology. BP had the advantage of developing their stats publicly, at least initially, so that analysts were aware of them. Hockey's a bit more obscure...


Monday, February 9, 2009

Past Recessions

Friday, February 6, 2009

More Gladwell (spoiler: he's wrong)

[This originally appeared in the "Committed Indian", the unofficial Chicago Blackhawks program...]

If you've got a friend in business - sales guy, MBA, doesn't matter - you've probably heard him talk about Malcolm Gladwell. Gladwell writes books about unintuitive things: his 2005 book Blink, was, if I recall correctly, about how thinking too hard on the job causes people to make more mistakes. Some of you might remember that line of thinking from Bull Durham. At any rate, Gladwell's most recent book, Outliers, is about how success is a combination of both talent and surprisingly more opportunity than we expected.

One outlier he identifies is the distribution of NHL players' birthdates: for decades, NHL players have been twice as likely to be born in the first three months of the year than in the last three. The reason why is fairly obvious - because little kids are divided into teams on the basis of what year they were born, the kids born earlier in the year are, on average, bigger and stronger and have almost an extra year of development. So they're the most likely to get picked by coaches focused on having the best team over the new few months. That leads to better coaching and competition and ultimately being more likely to get picked for a better team the next year.

This effect continues all the way through Junior hockey and the NHL, where the ratios of Q1 to Q4 birthdates are 3:1 and 2:1, respectively. Gladwell suggests that a lot of hockey talent is being squandered because professional players only started out a little bit better when they were kids but benefited tremendously from better coaching and competition. In an interview with ESPN, Gladwell said he suggested to officials from the Canadian national junior hockey team that they start a parallel league for kids born in the second half of the year, which would conceivably result in 150 additional NHL players if they equalized the first and second half birthdates. The officials supposedly told him it was "too complicated."

So splitting youth hockey into two leagues is too complicated even if it increases the number of players these leagues graduate to the NHL by 30%? If only it were so simple. The ratio of early-to-late birthdays is much higher in junior hockey than it is in the NHL, and so while the player development process may favor the older players from age 5-18, the jump from junior hockey to the NHL actually favors players born later in the year.

It's not surprising either - a player like Patrick Kane, who was born at the end of December, suddenly gained an extra year of development compared to a player who was born in January of the same year. And, after all those years playing in leagues where coaches were only concerned with how good you were going to be this season, the NHL is really only concerned with how good you're going to be at your best, which is usually when you're in your early-to-mid-20s. Even without the extra season, if you have two players with identical statistics in junior hockey, the December player projects to score 50% more points in the NHL than the player born in January, largely because he's put up those points against competition that's relatively bigger and stronger than he is.

Now remember that we're talking about all NHL players, including anyone who plays in even just one game. If we only look at former Canadian junior players who were in the top sixth in NHL scoring, which was anyone with 42 points or more last year, the ratio of early-to-late birthday players over the last decade is about 1.20:1. If we managed to equalize these two groups over the course of the next 25 or 30 years, that would ultimately add about seven Canadian players to the top sixth of the league. That's nothing to sneeze at, but it's not as if, as Gladwell suggested, we're "squandering the talents of hundreds of boys with late birthdays" by not doing so. It turns out that the group where players with early birthdays are most over-represented is the league leaders in penalty minutes per game, and I can't see anyone getting up in arms about whether some kid's December birthday kept him from becoming the next Ogie Ogilthorpe.

Labels: , ,

Thursday, February 5, 2009

Top 25 Fights on (2006-2009)

This isn't exactly a statistical post, but I was looking over (purportedly the 7th-most popular hockey site on the internet) and I noticed that there was no way to rank fights based on user rankings. I'm surprised - you'd think the hockey fight "Hall of Fame" would be one of the most viewed pages on the site. Well, here are the top 25 fights of the last three seasons based on user ratings:
Nov 26 2008Daniel CarcilloDerek DorsettDraw9.2Video
Oct 27 2007Riley CoteShawn ThorntonShawn Thornton9.1Video
Jan 15 2008Krys BarchBrad MayDraw9.0Video
Oct 14 2008Riley CoteEric GodardEric Godard8.9Video
Jan 3 2008Darcy TuckerJarkko RuutuJarkko Ruutu8.9Video
Oct 30 2008Eric BoultonColton OrrColton Orr8.8Video
Nov 25 2007Eric GodardD.J. KingD.J. King8.8Video
Dec 7 2006Josh GrattonJim VandermeerJim Vandermeer 8.7Video
Nov 15 2007Colton OrrRiley CoteColton Orr8.4Video
Nov 8 2007Riley CoteArron AshamArron Asham8.4Video
Jan 6 2007Jamal MayersJordin TootooJordin Tootoo8.4Video
Jan 10 2009Craig WellerJared BollCraig Weller8.3Video
Dec 22 2008Daniel CarcilloJason StrudwickJason Strudwick8.3Video
Nov 22 2008Donald BrashearJody ShelleyDonald Brashear 8.3Video
Oct 13 2007Brian McGrattanColton OrrBrian McGrattan8.3Video
Feb 3 2007Travis MoenShea WeberTravis Moen8.3Video
Mar 15 2008Riley CoteShawn ThorntonShawn Thornton8.2Video
Mar 10 2007David KociJosh GrattonDavid Koci8.2Video
Dec 26 2006Shawn ThorntonMark BellShawn Thornton 8.2Video
Nov 4 2008Garth MurrayEric NystromGarth Murray8.1Video
Mar 19 2008Brad MayKrys BarchDraw 8.1Video
Nov 21 2007Brad MayKrys BarchKrys Barch8.1Video
Oct 20 2007Georges LaraqueDonald BrashearGeorges Laraque8.1Video
Feb 27 2007Todd FedorukChris SimonChris Simon8.1Video
Dec 12 2007Mike FisherScott WalkerMike Fisher8.0Video

Note that in many cases, the videos have been removed by Youtube (perhaps due to excessive traffic generated by


This page is powered by Blogger. Isn't yours?

Subscribe to Posts [Atom]