Comments on: An Introduction to Rate Stats http://www.countthebasket.com/blog/2007/11/11/an-introduction-to-rate-stats/ Advanced Stats for Basketball Sat, 31 Jul 2010 18:11:24 +0000 http://wordpress.org/?v=2.5 By: Eli http://www.countthebasket.com/blog/2007/11/11/an-introduction-to-rate-stats/#comment-20 Eli Sat, 01 Dec 2007 03:41:55 +0000 http://www.countthebasket.com/blog/2007/11/11/an-introduction-to-rate-stats/#comment-20 That is an important distinction. I lumped per possession rates into the time-period rates because I think they share a lot of similarities to them. They may have the advantage of controlling for pace, but the basic idea is still successes per time-period (where the time-period is marked by when possession of the ball changes hands). Though sometimes per possession stats are more like opportunity rates than time-period rates - for instance, though I listed it under time-period rates, points scored per possession can be seen as the successes of points divided by the opportunity of a possession. And you're right to note that per possession stats are often more useful than per minute ones. In the case of rebounding, I agree that rebounds per minute can be misleading. Rebounds per possession is an improvement, and rebounds per rebound opportunities (total team and opponent rebounds while the player was in the game) is even better. My latest post has some more discussion of rebounding. For steals, I like to use the opportunity rate of steals per opponent play while the player was on the court, where oppPlay = oppFGA + .44*oppFTA + oppTO (all scaled down by the percent of his team's minutes that the player played). That is an important distinction. I lumped per possession rates into the time-period rates because I think they share a lot of similarities to them. They may have the advantage of controlling for pace, but the basic idea is still successes per time-period (where the time-period is marked by when possession of the ball changes hands). Though sometimes per possession stats are more like opportunity rates than time-period rates - for instance, though I listed it under time-period rates, points scored per possession can be seen as the successes of points divided by the opportunity of a possession.

And you’re right to note that per possession stats are often more useful than per minute ones. In the case of rebounding, I agree that rebounds per minute can be misleading. Rebounds per possession is an improvement, and rebounds per rebound opportunities (total team and opponent rebounds while the player was in the game) is even better. My latest post has some more discussion of rebounding.

For steals, I like to use the opportunity rate of steals per opponent play while the player was on the court, where oppPlay = oppFGA + .44*oppFTA + oppTO (all scaled down by the percent of his team’s minutes that the player played).

]]> By: mark http://www.countthebasket.com/blog/2007/11/11/an-introduction-to-rate-stats/#comment-19 mark Fri, 30 Nov 2007 21:08:56 +0000 http://www.countthebasket.com/blog/2007/11/11/an-introduction-to-rate-stats/#comment-19 Great article, I think how you break down the different categories. Just one thing. I think the there might be another category that takes into account the pace of the game (similar to time rates, but on a per-posession basis rather than per-minute) somewhat akin to time-period rates. Stats like rebounds, assists and steals, which don't lend themselves well to opportunity rates due to the lack of an easily quantifiable failure metric, can also be a little misleading when converted to time period stats. For example, Shawn Marion has an inflated rebound total because phoenix typically has more posessions to play with. So measuring rebounds as a percentage of the total number of rebounds in the game or total number of posessions in the game seems better than the number of minutes. Just an idea. Cheers, Mark Great article, I think how you break down the different categories.

Just one thing. I think the there might be another category that takes into account the pace of the game (similar to time rates, but on a per-posession basis rather than per-minute) somewhat akin to time-period rates.

Stats like rebounds, assists and steals, which don’t lend themselves well to opportunity rates due to the lack of an easily quantifiable failure metric, can also be a little misleading when converted to time period stats.

For example, Shawn Marion has an inflated rebound total because phoenix typically has more posessions to play with. So measuring rebounds as a percentage of the total number of rebounds in the game or total number of posessions in the game seems better than the number of minutes.

Just an idea.

Cheers,
Mark

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