Bill Belichick says he has ‘no explanation’ for Deflategate

Bill Belichick said he did not know how the Patriots’ footballs became underinflated in Sunday’s game. By Matt PepinGlobe Staff January 22, 2015

Coach Bill Belichick said he did not know of any issue with the Patriots’ game balls in Sunday’s AFC Championship, and did not learn the league was investigating his team until Monday morning.

He also said he did not know how the Patriots’ footballs became underinflated during the game.

It was Belichick’s first appearance since news emerged that 11 of 12 footballs the Patriots used against the Colts in the AFC Championship were underinflated. He gave a lengthy opening statement, but responded to questions only by saying he had no more to say about it.

“When I came in Monday morning, I was shocked to learn of the news reports about the footballs. I had no knowledge whatsoever of this situation until Monday morning. I’d say I’ve learned a lot more about this process in the last three days than I knew or had talked about it in the last 40 years,” Belichick said.

Bill Belichick said he did not know how the Patriots’ footballs became underinflated in Sunday’s game. By Matt PepinGlobe Staff January 22, 2015

Coach Bill Belichick said he did not know of any issue with the Patriots’ game balls in Sunday’s AFC Championship, and did not learn the league was investigating his team until Monday morning.

He also said he did not know how the Patriots’ footballs became underinflated during the game.

Patriots coach Bill Belichick spoke to the media Thursday morning on issues surrounding underinflated balls used during the AFC Championship game.

Belichick said he does not concern himself much with the condition of game balls, although he acknowledged players would have a greater interest in it.

“I think we all know that quarterbacks, kickers, specialists, have certain preferences on footballs, they know a lot more about it than I do, they’re a lot more sensitive than I am, and I hear them comment on it from time to time, so I can tell you, and they will tell you, that there is never any sympathy whatsoever from me on that subject,” Belichick said.

Belichick said he did not know quarterback Tom Brady’s preferences for game balls.

“Tom’s personal preferences on his footballs are something that he can talk about in much better detail and information than I could possibly provide,” Belichick said. “I can tell you in my coaching career I have never talked to any player, staff member, about football air pressure. That is now a subject that I have ever brought up. To me, the footballs are approved by the league and game officials pregame, and we play with what’s out there. And that’s the only way I have ever thought about that.”

Belichick said prior to this issue emerging, he was unaware of the exact process by which game balls were prepared and handled.

“Let me just say that my personal coaching philosophy and my mentality has always been to make things as difficult as possible for players in practice, and so with regard to footballs, I’m sure that any current or past player of mine will tell you that the balls we practice with are as bad as they can be. Wet, sticky, cold, slippery, however bad we can make them, I make them,” Belichick said. “Any time the players complain about the quality of the footballs, I make them worse.”

Quarterback Tom Brady is scheduled to meet with the media on Thursday at approximately 4 p.m.

The effect of temperature on football inflation.

Assume that the game footballs were inflated in a 75 F degree locker room, then taken out to a playing field at a temperature of 50 degrees F. How much would the change in temperature decrease the pressure in the football?

High school physics tells us that the ideal gas law PV=nRT applies. That is, pressure times volume is equal to the number of moles times the gas constant times the temperature of the gas (in degrees Kelvin). Thus, given a constant amount of air in the football and a negligible volume change, the pressure will obey:

P = nRT/V
The change in pressure is thus proportional to the change in temperature,
The 75 degree locker room has an absolute temperature of 297o K
The 40 degree playing field has an absolute temperature of 283o K
The change in temperature of 14o K will thus cause a drop in pressure of 14/297 = 4.7%.

To translate this into a pressure change we must recall that football pressure is measured in gauge pressure, relative to the atmospheric pressure of 15 psi. So the absolute pressure within a football pumped to 13 psi is 13 +15 = 28psi absolute. The 4.7% drop applied to the absolute pressure gives a drop of 1.32 psi. Thus, the pressure within the football at game time will be only 13 -1.32 = 11.68 psi and thus well below regulation gauge pressure of 12.5-13.5psi. If they were just at 12.5psi to start they would be down by 1.3psi to 11.2psi by game time. And of course, a little pressure is lost every time you stick a needle in to check the pressure. Some guy on TV did this calculation but I think he forgot about absolute pressure vs gauge pressure and underestimated it.

It thus seems highly likely that the Patriots equipment manager checked all 12 balls in a warm locker room and they lost pressure merely by cooling off on the field. In addition, the cold rain would have accelerated the heat transfer out of the balls. Finally, if the indoor inflation air was very humid, there would be an additional loss of pressure due to water vapor condensation on the inside of the bladder as the temperature of the football dropped.

I have to laugh at Fox News on-air personalities who routinely use “alleged” in conjunction with the most heinous crimes, but not used with the Patriots. According to Fox News they were guilty from your first report. The “homer” Brian Kilmeade — a dyed-in-the-wool Jets fan — is the worst.

Remember, the balls used in the second half were properly inflated and the Patriots scored 28 points.

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