Is Corsi losing its Correlation with Winning?

I had someone e-mail me today asking me why some traditionally good Corsi hockey teams are struggling. Any explanation for the NHL season thus far? I hate to use PDO, but is it just the year of PDO without much further explanation? I can’t believe how many traditionally sound possession teams are struggling this year, Dallas really surprised me and of course as a Blues fan seeing Chicago faring so…

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Predictive Analyics have failed Hockey Analytics

A few weeks ago I wrote about the limitations of predictive analytics. Go read that if you haven’t. Here are some areas where predictive analytics has failed hockey analytics. Gabe Desjardins used predictive analytics and suggested one must regress on-ice Shooting Percentage 80% towards the mean. I found that player on-ice shooting regressed 80% to the mean…   Eric Tulsky used predictive analytics and suggested one must regress on-ice shooting…

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Limitations of Predictive Analytics in Player Evaluation

Hockey analytics generally revolves around identifying what statistics are best at predicting future events, or “out of sample” events more generally. The main reason that Corsi has become such a popular statistic in hockey analytics is because it is more predictive of future events. We look at score and venue adjusted Corsi because we have found that they are more predictive. Many people have developed “expected goals” models and are adoping…

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Theoretical Problems vs Real Problems of the Toronto Maple Leafs

I am taking a bit of a hiatus away from my hiatus on blogging because I read something a few days ago that caught my attention both as a Leaf fan and as a hockey analytics enthusiast and felt compelled to respond. The Leafs have been a pretty interesting team this year with a significant infusion of youthful talent in Matthews, Marner and Nylander. They may even be good enough…

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Going On Hiatus…

I just finished an 8-part series on roles and statistics with a specific intent of showing that certain types of players or playing styles have impacts on save percentage. It was received well by some, not so well by others. Clearly there are detractors however this is a case of been there, done that for me. I went through the same debates 5-6 years ago with on-ice shooting percentage. I am confident…

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Roles and Stats Part VIII: Review and Looking Forward

This is my 8th and final post in my series on the relationship between roles and statistics and this will be a review of what we have learned so far and maybe more important what it all means and doesn’t mean. Series Posts Part I: Background and Methodology Part II: Roles and Offensive Stats – Forwards Part III: Roles and Defensive Stats – Forwards Part IV: Roles and Offensive Stats – Defensemen Part V: Roles…

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Roles and Stats Part VII: Can roles predict future shooting and save percentage?

In the first six parts of this series I have looked at the relationship between roles and player statistics and, particularly for forwards, there is a clear relationship between how a player is used and their resulting statistics. Now this isn’t an absolute relationship as we saw with Brandon Sutter in part six of this series but it does exist. Thus far I have only presented an “in-sample” relationship (relationship…

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Roles and Stats Part VI: Who’s Who?

This is part six of my series on the relationship between roles and statistics. I recommend you read some or all of the previous posts before reading this one starting with my first post where I provide a background and the overall methodology of this research project. In this sixth post I want to look at which players are in some of the more extreme roles that have the most…

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Roles and Stats Part V: Roles and Defensive Stats – Defensemen

This is part five of my series on roles and stats. In part four of the series I looked at how roles relate to the offensive statistics of defensemen and found that there was a relationship however it was not nearly as strong as for forwards (as one would expect). Today I will look at roles of defensemen and defensive statistics which one would think ought to show a stronger relationship….

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