Answered December 26th, 2017

Entering tonight, the highest +/- by a Pistons player this season was +28. Tonight 3 players surpassed that mark: Andre Drummond +35, Tobias Harris +29, Reggie Bullock +29.

Highest +/- in a game by a Pistons player this season
Interpreted as:
Highest + / - in a regular season game by a Pistons player this season