I really like this stat. Thanks for putting it up!

I find it interesting as well but I'm watching the replay of the game right now and it outlines the problem with it, particularly in small sample sizes. 

Mo left the game with just over 11 minutes to go in the first half with the game tied at 21 and Setty replaced him.  While Setty was in there were 5 total possessions (three for Toledo and two for Ohio).

1. Ohio in zone.  Weatherspoon pops up out top after Brown (I think) cuts down the lane and draws both guards down with him. Weatherspoon hits a wide-open three.

2. Travis Wilkins makes a nice move and gets an open ten foot shoot but misses.  The rebound goes high in between three Rockets where they corrall it. Setty actually made a nice hustle play coming from the weak side to knock the rebound out of the Rocket's hand but it goes off the tips of his fingers out of bounds.

3.  Weatherspoon gets Setty one on one down low on the right.  Setty overplays Weatherspoon's left hand since he's a lefty and he gets schooled for an and 1.  Great move by Weatherspoon though.

4.  Easy pass from the top of the key to Bean on the elbow and he just lets it go through his hands for a turnover.

5. Williams takes Bean off the dribble and hits a circus shot in the lane.  Timeout and Ndour returns.

So essentially Setty only had a negative impact on one play but gets a minus 8 in just over a minute.

Excellent overview Van - the stat is also impacted by who you replace in the line-up.  Since N'Dour is out, Setty is almost set up to have negative numbers.  Key as you said is also "small sample." 

When you look at it on a small scale as Van did, it will make your head spin and and sometimes not make a lot of sense.  But the bottom line is over the long run, good players make teams better...and the way a team improves is by scoring more than their opponent.  If you have a player making all kinds of mistakes on both ends of the floor all season long, it is bound to show up in a poor plus/minus for the season eventually.

I remember that and believe I said out loud, "Where are the points going to come from with this group on the floor?"

I like Bean, Setty, Campbell from somewhat to a lot but the +/- per minute in that short stretch that they were on the floor together must have been some kind of high, negative number.