Net PER is a severe statistic. It factors in defense (what your man is doing) in addition to scoring, shooting %, turnovers, fouls, rebounds, etc.
Net Per is your PER minus the PER of the man that you are guarding.
+11.3 Brook Lopez (All-Star)
+9.6 Deron Williams (All-Star)
+6.3 Jason Terry (he's not this good, will come down from here)
+5.5 Paul Pierce (where you'd expect him at this point in his career)
+3.1 Mason Plumlee (only 35 minutes, so may not stay here. This number is not due to his offensive prowess. Rather, the men that Plumlee has guarded have missed shots or made turnovers)_______________________________________________________ Look at the great divide between the 5th best and 6th best players so far, this is too big a gap
-4.7 Andrei Kirilenko (strange: only 52 minutes, but had been +4.4 or better for 11 straight seasons)
-5.4 Joe Johnson (he has to win his matchup - this can't continue)
-6.2 Shaun Livingston (surprise, you thought that Shaun looked good on offense, but he's getting torched on defense)
-6.3 Alan Anderson (this is sub-par even for Alan Anderson. Capable of better)
-6.6 Andray Blatche (coaching staff needs to take Andray aside for about 20 minutes per day for a month or two and explain he's shooting out of his effective range, he's dribbling too high so he gets picked clean, and Andray passes too often when a defender is hanging over a teammate, leading to a turnover followed by a break-away layup)
-12.4 Kevin Garnett (If KG were a horse Grandpa would take KG behind the barn, shoot him, and buy a new horse. But KG's not a horse. Don't know why he fell off the cliff. Was +5.5 last year. Was shooting 49% last year versus 30% this year, but KG was still an effective defender last year)
-16.3 Reggie Evans (Probably doesn't deserve to be on the court since he can't make a bucket)
-39.5 Mirza Teletovic (can't make a shot, chucks it up as soon as he touches it, doesn't set screens, doesn't take charges, doesn't pass; but heck, isn't he the best player in Bosnia, so why should he pass the ball to someone else or bother setting a screen for someone else to shoot or drive to the basket?)