Originally Posted by Gumby
I did not know that. Seems to invite shenanigans. I would think the referees should control the supply of game balls.
I also wonder if filling and measuring the ball pressure is done indoors at room temperature. If so, when you take them out into the cold, you would expect the internal pressure to drop. P1V1/T1 = P2V2/T2 and V is constant.
Agree 100% should be all be the same for both teams. MLB does not allow pitchers to supply their own balls, why should NFL?
FWIW- Temp difference does not explain "Deflategate".
Game time temp was 51F, or 21deg below room temp.
NFL spec ball pressure is 13psi +/- 0.5psi.
According to Ideal Gas Law:
PV/T= C (constant)
since V of a football at rest is constant, P2/T2=P1/T1, or P2= P1 * (T2/T1)
T is absolute Temp (i.e. degrees above absolute zero, -459.67F).
Assuming refs testing balls at room temp at NFL's 13psi, we would have on field ball pressure of
Even allowing the specified 0.5psi tolerance, Pat's balls (reportedly) at 11psi would still violate league rules.
Not that it mattered to the game's outcome, but rules are rules.