Monday, October 26, 2009

An Update on Faceoffs

My last post discussed the importance of faceoffs on winning in the NHL, and looked at data for the current season to see what was happening at the empirical level. As we discovered, winning faceoffs had only a slightly positive correlation with winning, and that the variability around the estimated effect was very high.

As promised I took a look at a larger data sample to see what effect winning faceoffs had on winning games. I used data for the 2006-07, 2007-08 and 2008-09 seasons and found some interesting results. Below is the chart showing estimated standings points based on the coefficients estimated from a regression using face off wins and number of face offs taken as control variables. While the coefficient of determination for this regression was low with an R-Squared was around 9% (meaning that around 90% of the variability in the model was not captured by winning face offs), all of the dependent variables were statistically significant at the 5% confidence level.

As can be seen, the positive correlation seen in the data from this year is emphatically washed out by data for a 3-year period. There is really no discernible conclusions to draw from the statistics over time other than face offs do not have a very meaningful effect on winning, as a stand alone measure.

I have some trouble accepting the conclusion that consistently winning face offs through out a season does not lead to more opportunity to win. Perhaps a more telling statistic would be percentage of games that a team wins the head to head face off win category, as that may smooth out any noise introduced into the model by specific games which feature a lot of face offs (this is, on a team by team basis controlled by the model, but not on a specific game by game basis) and will isolate who was better that game, which have more implications on winning. As it is measured now, as a summation of wins across a season, may erase the descriptive value of the statistic.

Also, face off wins are not seperated by a win in a scoring zone versus the neutral zone. If the neutral zone face off wins were taken out of the model, thus removing face off scenarios which are less likely to lead to scoring situations, we may see more correlations to face off wins leading to wins. These are studies which are heavily data intensive and thus are time consuming to execute, however I think that this is a fascinating aspect  of the game to examine, and that there are value-centered results that can come from finding meaningful analysis to what the data show. Time to dig deeper.

Tuesday, October 20, 2009

The Importance of Faceoffs

A statistical topic that I have frequently heard arise in conversations about this young season is the importance of winning faceoffs. Anyone who has played the game at a high level, and really anyone that is an experienced spectator of high level hockey understands that winning faceoffs are one of the little things that have a tremendous impact on the game. However, I started thinking, what can winning faceoffs really show in terms of winning (measured by standing points) in a statistical sense. Taking the faceoff data for this year (yes i know it is a small sample size), I ran a regression which estimated standings points controlling for faceoffs won and the number of faceoffs taken. From there I plotted the number of faceoffs won by each team and their actual standings points, along with the estimated standings points derived from the linear coefficients from the regression.

As you can see from the line showing estimated points, there is an overall slightly positive correlation between winning faceoffs and winning games. However, looking at the line showing actual points, there is a high degree of variability as a team wins more faceoffs. While heavily robust conclusions cannot be drawn from this data because of the sample size, my initial thoughts are that simply winning faceoffs really does not have a profound effect on winning games, and is a statistic that while may help proxy for who is working harder in the circle, or even which team is controlling puck play, does not capture enough intangible exogenous factors to be significant in terms of wins. If this is accurate, than the next time an analyst blames a clubs poor play (or some aspect of their play, i.e. power play or penalty kill) on the inability to win faceoffs, you may want to question whether that is really the issue, or if there are more significant factors that are causing that team to lose games.

I plan on expanding on this study throughout the season, and will perhaps venture to look at seasons past as well.

Friday, October 16, 2009

Stars-Bruins Rematch

Yes I know that Steve Ott is hurt, and that Sean Avery is back in the Big Apple, but I think there will be some fire from the Stars for sure to avenge the loss from last season that started their downward spiral into an out-of-sync hockey club.

If you remember, after this game, which featured a combined 146 penalty minutes, Mike Modano, a generally quiet guy called out his team for turning the game into a circus. While I don't see a similar outcome happening this year, in terms of shenanigans, I think this will be a spirited game. If we are lucky Krys Barch will continue his best big bully impression by beefing with Milan Lucic. Barch has only dropped the gloves once this year, and it did not go well, but look for him to bounce back with a big bout. To his credit, Barch did take on Sheldon Souray (or Studly McWonderbomb if you have ever heard Daryl Reaugh call a Dallas - Edmonton game), who tossed him around a bit before they were seperated.

Anyway, look for the Stars top 6 to overwhelm the Bruins defense, and for Turco to continue the top form of play that he displayed on Wednesday against the predators. If the Bruins are going to break out of their early season funk, they are going to need to capitalize against the Stars shaky penalty kill, and limit the Stars forecheck by having Tim Thomas help move pucks out of the zone. While the Bruins power play may help keep them in the game, I dont think the Bruins are ready to handle the Stars forward pressure in their first road game, especially with the confidence that the Stars wingers have shown early one. My prediction is a 4-1 Stars victory.

Enjoy the game.

Wednesday, October 7, 2009

The Blog

As can be seen from the title and the about me, this blog will be devoted to the intersection of hockey, business and economics. I hope that my ideas about how the game is played and is measured and analyzed are both interesting and thought provoking and contribute to the enrichment of the hockey universe. Enjoy!