28 October 2011

Coming full circle on NU's 2010-11 efficiency


Carmody Courters – we thank you for your kind words about our article on NU’s 2010-11 defense.  We hear you, and we are here for you.  First things first – yes our trend line analysis of the defense was statistically significant.  The F test exceeded the critical level, and the t statistic for the slope was 1.75 -- significant at a 90% confidence level.  Note that if we were to drop the games against the Evil Bo Ryaners from the analysis (Ha! Don't we wish!) then the fit shoots through the roof and significant with over 95% confidence.  

Second, you asked for it and below is a similar analysis of NU’s 2011-12 offensive efficiency.  The chart below shows NU’s game-by-game offensive PPP performance adjusted for differences in the quality of the opponent’s defense.  Now, before all you readers get all hot and bothered again about it, let’s say up front that the trend line is NOT statistically significant.  Even if it were significant the very flat positive slope wouldn’t exactly tell a compelling story.  

 Still there are some interesting nuggets that have been dug up by our completing the circle of analysis on NU’s 2010-11 efficiency.  First, the randomly moving solid line is what one would expect to see from an offense that is neither improving nor regressing.  Second, save for an embarrassing offensive performance in Nittanyville the offense had equal ranges for under- and over- performance.  

In what may come as a surprise to folks NU outperformed on offense in 12 B1G games and underperformed in 8 B1G games.  How could this be?  After all NU was ranked by kenpom as the 18th best offense in all the land and third best offense in the B1G.

The reason for the rather lackluster offensive performance is that NU’s kenpom statistics were largely based on NU’s offense feeding on non-conference cream puffs.  If you look at just the B1G games NU’s offense only ranked 7th in efficiency.  In short, NU’s offense was not the juggernaut that some may have falsely believed.  

Our last tidbit is how starkly this chart sheds light on NU’s woes against the Nit Wits.  While the Fightin’ Ed DeChellises performed better than expected against NU’s defense last year, the true reason for PSU’s domination of NU was its solving the riddle of NU’s offense.  NU underperformed on offense by an eye popping 0.39 PPP in State College and managed to narrow that underperformance slightly in the rematch at the Welsh to the tune of a 0.19 PPP offensive underperformance.  These two blights on the chart are encircled in Nittany Blue (or symbolic of the bruises that PSU defenders left on our blocked cutters?).  Thankfully NU no longer needs to worry about Ed DeChellis and his mastery of Coach Carmody's schemes.  The curse will be lifted this year!

For 2011-12 the hope on offense is that some combination of Marco, Cobb, and one of the frosh guards can step into Juice’s shoes and facilitate the offense and knock down some important shots from deep and runners in the lane.  Time will tell.  Certainly a healthy Shurna and Cobb would help greatly in filling in the gaping hole left by Juice’s departure.