Friday, June 20, 2008

Team Performance Update

I've finally started to get around to posting final stats for the 2007-8 season. I've run into a bit of a snag, in that I don't have 1st half / 2nd half split box scores for the NCAA games (Tom Gower, help!!), so I've only posted the final performance charts.

A few points:
  • Before I get into the details of Georgetown's perfomance this season, I thought I'd direct my reader's attention to a post on VBTN (yes, a month ago), reviewing Big East teams' offensive and defensive ratings. greyCat may have the axes mislabelled, but he does a nice job explaining the relative strengths of the 16 BE teams. In a nutshell, Louisville and G'town played defense at a much higher level than the other 14 teams, while G'town's offense was only slightly better than league average. I believe that greyCat is using the entire season for his analysis, and I'd like to see his analysis reworked for only conference games, as the non-conf. SOS varied widely.
  • The winner(?) for worst game of the season goes to the BET final against Pitt, where the Hoyas were more than 13 points worse than expected. This number is likely skewed by the fact that Pitt was playing much better at that point due to the return of Levance Fields - indeed, this is a great example of a shortcoming of using Pomeroy's stats to predict performance, as his system isn't "aware" of injuries.

Finally, I thought I'd break down the team's performance into their four factors, aggregated by performance. I've separated the season into 3 chunks, good performances (> ~3 pts. above expected), poor performances (< ~6 pts. below expected) and middling (those games in between). This is somewhat similar to KenPom's correlations, found at the bottom of his game plan page, reprinted here for reference.
to OE to DE
Pace: +0.13 -0.08

eFG%: +0.71* -0.24
OR%: +0.32 -0.07
TO%: -0.44* -0.07
FTR: +0.09 -0.16

Opp eFG%: -0.03 +0.65*
Opp OR%: -0.26 +0.26
Opp TO%: +0.14 -0.55*
Opp FTR: -0.18 +0.33

Bold values are significant with a 95% confidence
Bold* values are significant with a 99% confidence

First, general info:
          Good  Middling  Poor
Record 11-0 10-2 7-4
Pom Rank 100.0 92.6 91.0
Pace 64.8 62.9 61.9
Even when Georgetown played poorly they usually won; since performance accounts for opponent quality, a close win against a big underdog would be considered a poor performance. The Hoyas best games came against the weaker teams, but this is a small effect. Faster pace seems to track performance (the "good" pace appears significantly faster).

Next, offense:
          Good  Middling  Poor
OEff 121.1 114.4 104.1
eFG% 60.9 58.2 53.9
OR% 33.3 32.9 30.8
TO% 19.4 20.8 22.8
FT Rate 25.2 22.3 24.1
It's no surprise that Offensive Efficiency tracks performance; after all, it represents half of performance. As Pomeroy suggests, eFG% shows a good correlation with OEff, the other factors less so. What can be seen here is that the Hoyas shot well even in average games, but poor shooting meant poor performance. Georgetown shot 34% (76/223) on 3FG in their poor performances, versus 40% (193/478) in other games; the Hoyas were 54th of 341 teams in dependence on 3FGs, and this shows here. I was expecting a bigger difference in TO% (turnovers committed), but the effect seems small here.

Finally, defense:
          Good  Middling  Poor
DEff 85.9 90.1 98.9
eFG% 37.0 42.0 42.8
OR% 34.1 32.1 31.0
TO% 21.8 22.0 15.5
FT Rate 39.1 35.6 39.0
The difference between middling and poor defensive games wasn't opponents' shooting or defensive rebounding, but turnovers forced. I didn't expect that, although the Davidson game would be a clear example of this. When Georgetown played very well, their opponents had a miserable time putting the ball in the basket.