Mr Intangibles is what I'd call him. What he brings to a team has rarely been measurable quantifiably.
People keep stating this as if it's fact. It IS measurable quantifiably and the measurements show is this:
Perkins is a liability on offense. Fine, he's not an offensive player. But before, at least he wasn't a liability offensively. Now, he is.
He is blocking shots below his career average.
He, as of this year, has been a terrible rebounder for his position. Just awful.
Every sabremetric shows him as one of the worst players in the league.
The only number in his favor is the fact that the defense is clearly better with him on the floor. A couple problems with this is that this can't be solely attributed to him - it may speak more to the defensive weaknesses of the other big men on the team. And also, the Thunder are at best - an average defensive team. Meaning, Perkins is such a liability in other facets of the game that he can't stay on the floor all that much (28 minutes a game).