Challenging a play question

I could not find it either. I'll bet Big Ben has an idea. I would guess that close to 40% are overturned. There are lots of close plays that in real time are hard to tell whether safe or out. Being each coach has 2 challenges per game. I assume that most teams use their two challenges. So multiply the number of games played by 3 (assumed average number of challenges used per game).

Easily 50%. After all
Theses guys are butchers,bankers, insurance salespeople, plumbers. They stink but they cheap.