Wednesday, October 6, 2010

Big 12 Prediction and a Quick Review of the Model

My model is incredibly simple. The idea is that

Efficiency =
f{Player Talent, Coaching}

Thus the difference between any two seasons is

Change in Efficiency =
f{Players lost, Player development, Incoming recruits, Coaching changes}

When evaluating players lost, I look at the possession-weighted tempo free statistics of the departing players. This is critical because when a team loses a very inefficient scorer (think someone with an 85 ORtg), that is not going to have a negative impact on the team. But if the team loses a player with a 120 ORtg, that will hurt a lot. And because it also matters how often a player shoots, I weight by the percentage of possessions used over the full game. (This incorporates both percentage of minutes and percentage of possessions on kenpom.com.) This year in addition to the tempo free offensive player statistics, I also include the tempo defensive player statistics in the model.

Player development emphasizes the fact that the biggest leap is often from freshman to sophomore year.

And I include incoming recruits which is simply a measure of the average impact of RSCI top 10 and top 100 recruits.

Finally, my model also accounts for coaching changes. On average, new coaches tend to have a negative impact on the offense. (It can take time for the players to learn a new offensive system.) But successful veteran coaches will usually improve the defense in the first year.

Today I present the model’s predictions for the Big 12.

Big 12 Prediction

For the record, I do not include Josh Selby for Kansas and Tony Mitchell for Missouri based on the fact that neither has been cleared academically. I’m currently still including LaceDarius Dunn of Baylor, but after yesterday, that may be a mistake. (These player eligibility issues are becoming more irritating by the day.)

The first table lists the changes we should expect this year based on players leaving and other factors. Texas Tech loses almost no key players, and should be better. But there are a lot of teams that are not so fortunate. Iowa St. loses a ton of talent, and unless I’ve read things incorrectly, transfers Chris Allen and Royce White will not be eligible until next year. That means there is really no reason to expect Iowa St. to be better this year.

And no Big 12 team lost as much talent as Kansas. Kansas will still be very good. After all, they did have the top Sagarin rating in the nation at the end of the regular season. But with Cole Aldrich, Xavier Henry, and Sherron Collins leaving in the off-season, Kansas will take a significant step back.

Texas and Baylor also lose a lot of talent, but Texas adds a pair of Top 15 recruits in Tristan Thompson and Cory Joseph. And Baylor adds Top 10 recruit Perry Jones.



Next I isolate the expectations for offense and defense. While Oklahoma St. loses two incredible scorers in James Anderson and Obi Muonelo, they should return two of the best defensive rebounders in the nation in Matt Pilgrim and Marshall Moses. While the Oklahoma St. offense is expected to slip a little this year, the defense may be better.



Finally, I present the standings. As it turns out, these are eerily similar to how the Big 12 coaches voted. On the one hand, that is very comforting. This model is still in the experimental stage, so it is nice to see the model matches with what others are thinking. On the other hand, the whole point of the statistical model is to identify misperceptions, (things that other folks are over-looking). But in the case of the Big 12, the coaches seem to agree with what the statistics predict. Kansas St. is the favorite, and Kansas and several teams are within striking distance.

For me the interesting story this season will be Texas Tech. Pat Knight has an extremely senior-laden team, and he needs to make the NCAA tournament this year. Texas Tech is currently 7th in these projections, which would put them squarely on the NCAA tournament bubble. But with a few late bloomers, Texas Tech is not that far behind Baylor for 3rd place in the league. On the other hand, with a few injuries or players not living up to their potential, Texas Tech could have a new coach this time next year.