Monday, February 21, 2011

The Value of Corey Stokes

For Want of a Nail a Kingdom Was Lost
Senior wing Corey Stokes has been DNP-injury in the Wildcats' last three games (Pittsburgh, Seton Hall & DePaul), but the senior indicated that he pulled/strained a hamstring in the Cincinnati game (January 9), followed by a turf toe injury in the Wildcats' loss to Georgetown (January 29). Though his minutes declined from 34.3 to 30.1 (Big East conference games only), observers noticed a decline in his offensive efficiency (and defensive capability). Looking at Ken Pomeroy's efficiency stats, game-by-game for Villanova's 14 Big East games so far...

RecordAverage (Raw)
RU - Providence520.71468.
GTown - DePaul430.57161.

Seven games on both sides of the divide, but the difference shows just about everywhere, from the won-loss record, to the offensive and defensive efficiencies (points scored and allowed per possession), to the Pythagorean Winning Percentage. The numbers would suggest the greatest impact has been offensive, and many in the Nova Nation would agree the lack of a (more) consistent three point threat has diminished what the staff wants the offense to do most -- penetrate and finish/dish/pass into the low post. With an inconsistent threat on the perimeter, those teams who send help to stop dribble penetration are too often rewarded with a defensive stop. The drop in pace (possessions) is shocking -- a 10.2% decline in per game possessions this late in the season signals a dramatic change in playing style (or certainly in personnel in the rotation). Stokes is not noted for his end-to-end speed, but compared to the players who have taken those minutes, there is little doubt the offense was able to get a field goal attempt off earlier in the shot clock when Stokes was on the court. A comparison of Oliver's four factors, before and after for both offense and defense reveals a few more interesting things about the team's offensive and defensive efficiency...

On Offense
Thru PC52.419.038.148.4
Thru DePaul51.319.637.148.3

The deline in shot conversion efficiency (eFG%) is understandable -- Stokes was one of the best in conference prior to his turf toe injury. Pulling a sophomore off the bench and expecting him to pick up that role without missing a beat is unrealistic (and unfair). The slightly higher turnover rate may, like the lower pace, reflect a renewed commitment to a low post-oriented game. Entry passes get deflected and stolen. The decline in the rate of free throws to field goal attempts, very modest, may derive more from losing games. The team behind tends to commit "possession fouls" at the end of a close game. Villanova's additional loss has diminished the need to foul.

On Defense
Thru PC45.919.132.741.5
Thru DePaul47.216.630.834.0

The change in virtually every factor defensively is interesting, and unlike the offensive factors, where most changed at the margins, here I found rather significant movement in several stats. Note the declines in turnovers and free throw rate -- both suggest the defense has become more passive. Passive defenses do not force turnovers and put the other team on the line. One would expect, with the additional loss, to see a slight uptick in the defensive FTA/FGA (remember the possession fouls?), but it does not show here. I did find better defensive rebounding (a lower ORb% on the defensive side is a better number). Most likely a reflection of the longer players seeing more court time.


Raul Chavez said...

I got different defensive ratings/points per possession than you while Stokes was out. Is that raw pp our adjusted?

greyCat said...

Raw ppp Raul. Maybe we counted different games? I looked not only at the 3 Corey was DNP, but the 2-3 prior games where he was clearly not logging his usual share of time. I averaged the offensive and defensive efficiencies for the games in each group and took the net from the average.

Given that offensive eFG% has a high correlation to Villanova's offensive efficiency and to whether the 'Cats win, the drop of even 1% has had an impact.