Free throws and “Luck”

In light of today’s great post on Free Throw Plus by John Ezekowitz, I thought I’d share something I noticed a couple days ago. I had heard some Twitter chatter about Illinois consistently ranking low in Ken Pomeroy’s Luck metric, which essentially tells you which teams have tended to be on the right/wrong side of close games. (They’ve fared no better than 158th in the past 7 years.) It made me wonder if they were doing something specific that would lead to their low ranking. So, I decided to see if any of the stats kept by Pomeroy correlate to “Luck.”

Using 2010 team stats, here’s what I found. I highlighted SOS-related stats in yellow, offensive free throw stats in green, defensive free throw stats in red, and bolded tempo. The bars at the right represent the magnitude of the correlation, but keep in mind that the sign also matters:

Similarity Predictions

Since there were no tickets punched last night, I spent part of the evening developing an Excel workbook that makes game predictions based on how a team has performed in games against similar opponents.  I’ll use today’s game between Wisconsin and Illinois as an example.

First, I found the ten Wisconsin opponents whose offenses were most similar to Illinois, using the same method I’ve been using in the Tickets Punched series.  I then calculated Wisconsin’s individual game adjusted defensive efficiency against each of those opponents, using this equation (derived from the standard adjusted efficiency formula):

Wisc Game Adj Def Eff = [Opp Game Raw Off Eff] * [NCAA Ave Eff] / [Opp Season Adj Off Eff]

[NOTE: I actually treated HFA the same way Pomeroy does, but I didn’t want to make the equation look even messier]

Finally, I took a weighted average of those efficiencies, with the weight being the similarity score.  This gives me an adjusted defensive efficiency for Wisconsin that is specifically for games against offenses similar to Illinois.

I repeat the above process for Wisconsin’s offense, and Illinois's offense and defense, and the results all go into these pretty charts (where, as usual, green=good and red=bad):