PSI New England
They're calling it "Deflategate": The deliberate use of underinflated footballs to gain an advantage during a game. The accusers? The media and other haters of Patriot Coach Bill Belichick, Quarterback Tom Brady, the entire Patriot organization and their fans.
So what are the actual rules of football inflation? (not to be confused with the rising ticket prices, jersey costs, and other over-priced concessions) Here's the rule as it appears on www.nfl.com/rulebook/ball
"The home club shall have 36 balls for outdoor games and 24 for indoor games available for testing with a pressure gauge by the referee two hours prior to the starting time of the game to meet with League requirements. Twelve (12) new footballs, sealed in a special box and shipped by the manufacturer, will be opened in the officials’ locker room two hours prior to the starting time of the game. These balls are to be specially marked with the letter "k" and used exclusively for the kicking game."
NFL regulation balls are inflated to a pressure of between 12.5 and 13.5 psi (pounds per square inch). There is an allowable one psi variable that each team has in order to satisfy the demands of quarterbacks around the league. We now know Aaron Rodgers prefers his footballs be prepared on the high side, perhaps 13.5 and maybe then some. Rumors have it that Tom Brady prefers 12.5 and maybe something less.
I liken the NFL ball rule to the batter's box in baseball. A hitter is supposed to stand in the box, but as hitters dig in, the batter's box lines get distorted and batters wanting to stand beyond the "game time" box to gain an advantage, can do so. I've never witnessed an Umpire stopping play to reset the batters in the box or to have the batter's box re-lined. And so we play baseball despite what could be determined as an unfair advantage. Boxgate? Stay tuned...
Many Scientists have chipped in with their take on football inflation pressure, applying Chemistry and Physics to the equation. They have pointed out all the variables: pressure, temperature, volume, number of moles in gas, gas constant... Deciphering this information is not for the weak, it takes more than a football IQ and a fantasy update.
They begin by using the Ideal Gas Law pV=nRT, where p is pressure, v is volume, n is the number of moles of a gas, R is the Universal Gas constant, and T is temperature.
If pressure (p) is increased the temperature (T) would be increased as well. The change in volume (V) would also be responsible for a change in temperature.
Unless there is tampering during a game, the volume (V) of air should not change, ( n) will not change nor would (R). Scientists can simplify their equation by removing the unchanged variables (V), (n) and (R) and arrive at a more simple equation. In comparing locker room ball pressures to field pressure there are only two variables, temperature and pressure (inside the ball).
If the temperature inside the locker room during initial ball testing pre-game was greater than game time outdoor temperature, which was 51 degrees, then there would be a natural pressure drop inside the ball.
Using an indoor temperature of 68 degrees the equation would look like this:
{[(86,184.5 Pa + 100950.0 Pa) / 293.15 K] * 283.15 K} - 100950.0 Pa = p2
79,800.9 Pa = p2 ---> 11.8 psi
At 68 degrees indoor and 51 degrees outdoor there would be a .7 PSI drop at game time (11.8 PSI). If the inside temperature was 80 degrees the game-time ball pressure once brought outdoors would be 11.0 PSI and if the room was 90 degrees once brought outside it would have been 10.5 PSI at the start of the game.
It all gets very complicated, but the NFL has not been strict (think MLB batter's box) and it is safe to assume that game ball pressures throughout the league are very different city to city, given the 1 PSI variable the NFL provides and the differing locker -room to field temperatures. Imagine what a -1 at Lambeau would do to the game time PSI of a football!
In the end, what you need to know is that Indianapolis scored only 7 points against a tough New England defense and once the Officials put a new ball on the field, one that was properly inflated to start the second half, the Patriots scored 28 unanswered points, beating the Colts 45-7 to advance to the Super Bowl.
It would be better to spend time planning your Super Bowl menu than to try and sort this mess out. ( I'm thinking Eggplant Parm!)