Northwestern's victory last night over N.C. State gives us four games worth of plus-minus data against quality foes to look at. I'm controlling for quality because I don't want minutes against lesser competition to hurt the numbers, even if it does give a slightly smaller sample size.
Note: Big Ten Geeks has started doing some of their own plus-minus work and while Northwestern typically gets mentioned in the middle of all the other Big Ten teams, it's a good read for the statistically inclined.
Thanks to an engaged reader I have plus-minus boxes for all Northwestern games this season. I really appreciate the work that goes into calculating these, since it's not part of your common college box score. (Though it is in the NBA ones on ESPN.com.)
Thus far plus-minus reveals some interesting things that other statistics might not capture about four key players in Northwestern's rotation.
First off, how awesome has Alex Marcotullio been? The sample I'm working with includes a loss, so most players have at least one negative plus-minus game, but then there's Marcotullio. Even in the Butler game Northwestern played better when he was on the court. He has a total +/- of +35 in 84 minutes in those four games. He has given the Wildcats a lift in each game thus far. Maybe that's why his minutes have risen steadily - 15, 20, 23 to 26 last game - as the season has gone on.
Interestingly enough, according to +/- Marcotullio hasn't even been the best player on Northwestern's roster during those four games on a per minute basis. Davide Curletti has racked up an astounding +.95 per minute rate with a +/- of +19 in 20 minutes. Curletti didn't play against Notre Dame, but he racked up a +9 in 12 minutes against Iowa State. He and Marcotullio were the only players to have a positive +/- against Butler.
Then there's the bottom of the +/- barrel. A commenter astutely pointed out that he thought my evaluation of Kyle Rowley's play in Monday's post was incorrect and +/- appears to agree with him. Rowley has put up a miserable -23 in 44 minutes against top competition. The game against N.C. State was the only game in which he had a positive plus-minus rating and even then it was an up-and-down experience. (As this tweet demonstrates.) As a comparison, Luka Mirkovic has a rating of +19 in 98 minutes, but that's propped up by a great game against the Irish where he was +28 in 28 minutes.
Rowley isn't the very bottom of Northwestern's +/- list though. The man with the worst per minute rating is Ivan Peljusic. I thought Peljusic would be ready to contribute this season, but the team is averaging -1 point per minute in the 13 minutes he's played. He was the only player to put up a negative +/- against the Wolfpack at -2 in 3 minutes.
Plus-minus, like any advanced statistical tool, is just one piece of the puzzle, but these ratings seem to suggest things that are already apparent with astute observation. Expect to see more of Marcotullio as the season wears on.