Friday, January 13, 2006

Stats Don't Lie...Most of the Time

MCM, Pope and nearly every non-sports Blogger in America has directed my attention to the editorial by Larry David explaining why he isn't going to see Brokeback Mountain, which was quite entertaining. (The article, I mean. I haven't seen the movie).

In reality, I, like David, need to watch my step around that movie, not to mention the fact that I've now seen every syndicated episode of "Will & Grace" (of course, just because I always happen to be in the room when my wife is watching), as I think I already have something of a man-crush on a guy named Ken Pomeroy.

Part of the reason is that when I found his blog last year, he consistently had the most accurate College Hoops RPI numbers available on the net (that was before the NCAA made the RPI formula public for this year). As I continued to use his site daily, I got acquainted with his stats for "Offensive Efficiency" and "Defensive Efficiency", which are pretty simple, but to me, interesting. Now, has jumped on his bandwagon and within the last few weeks has hired him as a contributor. I guess my days of emailing him with questions about RPI scenarios will soon be long gone.

Ken says here more elequoently what I am now going to attempt to explain. Basically, the NCAA and nearly all media outlets report College hoops points per game and points allowed per game as a measure of which offenses and defenses more efficient. However, that stat does not take into account the pace of any game. Thus, if a team has more possessions, they are going to have more opportunities to score, and will likely have a higher PPG than a team with significantly less possessions per game, even if the latter team is more efficient.

Here are the formulas:

Offensive Efficiency(OE) = Points scored / (100 possessions)
Defensive Efficiency(DE) = Points allowed / (100 possessions)

Ken's site uses a "raw" number and an "adjusted" number for each of these stats. The raw number uses a team’s actual stats, not including games against non-D1 competition. The adjusted figure makes allowances for the competition faced, and in the case of efficiency, for the site of the game, and gives slightly more weight to more recent games. I prefer the raw number for crunching these numbers as I'm not quite sure how he accounts for these other factors.

Interestingly, Colorado ranks as the #2 offense according to the NCAA, but since they've tended to play at a bit of a crazy pace this year, they're the #20 in raw offensive efficiency. An example of a team that has a lot of success in a deliberate offense is Xavier, who is #6 in raw offensive efficency, but doesn't even make the NCAA's top 50 in points per game.

Defensively, the same things happens. When the NCAA Tourney rolls around, don't get suckered into picking Air Force as your big 13/4 upset because they have the #1 defense in the country. In reality, out of all 334 Division 1 teams, only Temple, Deleware St., Samford, Richmomnd and (as you might guess) Princeton play more of a slowdown game than AFA based upon the Pomeroy possessions per game statistics. That translates to Air Force having only the 49th best numbers in the nation for raw defensive efficiency.

In any case, this may or may not bore most of you, but I always am annoyed by the fact that so many pundits glean their predictions off of statistics like PPG in college basketball. I've got the same problem with the way the leaders Rushing Defense, Offense and Passing Defense and Offense are calculated by the NCAA football statistics department. I'm sure I'll post on that as football season draws closer.

Oh, and for you Husker fans:

-Nebraska plays at the 119th fastest pace in the nation. Right in the middle.

-Nebraska ranks as the 150th offense accorcing to the NCAA, but as the 170th according to Pomeroy's adjusted and raw numbers.

-Nebraska ranks as the 73rd best scoring defense according to the NCAA, but as the 21st best according to Pomeroy's raw efficiency number.


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