In his latest statements to the media, Wayne Chism noted that despite his 0-7 shooting from behind the arc against Kentucky, his presence on the perimeter opened up the lane for point guards Bobby Maze and Melvin Goins. He also mentioned that his leadership on defense helped the team beat the Wildcats. He wasn't bragging, he was simply stating that there are contributions to a team's success that aren't traditionally found in the boxscore.
That got me thinking back to something I'd first read in Dane Bradshaw's book Vertical Leap. Bradshaw mentioned how Bruce Pearl and his staff used something called plus/minus to measure the unmeasureables, to somehow gauge the impact of a player's overall contribution to the team while he's on the floor. The concept is to analyze indirect contribution by awarding a player a point for each point the entire team scores while that player is on the floor and to subtract a point for each point the opposition scores while that player is on the floor. The net result is that player's plus/minus for the game. Positive is good; negative is bad.
I have no idea to what extent Pearl relies on plus/minus to judge his players. There are certainly some deficiencies with the stat, namely that the best players are generally on the floor with the best players, so they are all helping each other. On the other hand, opponents are pretty good about finding weak links, and you'd think that that would show up in a team's overall performance. Regardless, if Dane Bradshaw says that it's important to Pearl, well, I believe Bradshaw and defer to Pearl.
I also don't know just how deep Pearl takes the concept. Some sites track not only a player's on-floor plus/minus, but also their on-bench plus/minus. Take a look at this plus/minus table from the Tennessee-Kentucky game, culled from the always fantastic StatSheet.com:
In the Plus/Minus section, the plus column shows the number of points the team scored while that player was on the floor. The minus column shows the number of points the opponent scored while that player was on the floor. The +/- is the net of the two.
The Off Court section is exactly what you'd think: the plus and minus columns show the team's and opponent's points while that player is on the bench, and the +/- column nets the two.
So what is the RR column under the Plus/Minus section? That's "Roland Rating," and it nets the on court and off court numbers, thereby giving a kind of overall plus/minus grade.
So, against Kentucky, Scotty Hopson and Brian Williams made the most positive overall contributions with an RR of 23, and J.P. Prince wasn't far behind with 17. Weezy, despite his awful three-point shooting, still managed a postive contribution. Kenny Hall, Skylar McBee, and Cameron Tatum, not so much.
But that'st just one game. How do the numbers look for the entire SEC season? Glad you asked:
Chism appears to have been the most consistent over SEC play, averaging the highest RR and getting only three negative contribution games. The second-best average -- surprise! -- goes to Pearl, but he's fallen off in the last four games. Fortunately, that's just when Pajamas and Hopson, who have both been on four game tears, have picked it up.
On the down side, Woolridge does not have a good RR rating, and you can see why Pearl hasn't been playing him much recently. Hopefully, he can get back on track and make the most of any late season opportunities that come his way.
Again, I have no idea the extent to which Pearl uses Roland Rating or even more standard plus/minus stats to judge his players' performances, but it is interesting to see how the team performs when any particular player is on or off the floor.
What do y'all think of RR and plus/minus generally? What are the strengths and weaknesses of the concept?