There needs to be more parameters than simply "push ups". In our fitness testing at the COPK classes our push up test is as many as you can do in 1 minute. You are allowed to rest but only in the up push up position. If you put your knees down or go to downward dog, you are done. Chest must barely touch the ground and arms must be fully locked at the top.

Adding to Ryan's comment

When down:
Chest, chin and thighs must barely touch the floor.

When up:
Arms must be fully extended (elbows locked), and body straight

There is also the hand and arms placement to be looked at here.  There are several ways one can do a PU and do way more than normal. e.i if you do it with very narrow arms placement and your palms are next to your rips rather than your pecks you can go forever.

So arms should be as wide as they would be if placed next to your shoulders and when down they should be next to the middle of you pectoral.

It'd be better to do Muscle Up count. Although we already know who is going to have way more. *calls out loud for Ryan*