Can temperature affect air pressure in footballs the way it affects air pressure in the houses we remodel? One of the best (and certainly one of the first) explanations of air movement in homes comes from building science pioneer John Tooley, whose research into what he called "Mechanical Air Distribution And Interacting Relationship, or "Mad-Air," alerted the residential construction community to the complex interactions between temperature, wind, and mechanical ventilation.
Many of the same principles are at work in Bill Belichick's "deflategate" claim, that underinflation of the balls used in the Patriots victory over the Colts was the result of a pressure drop caused by the 30-degree temperature differential between the room where the balls were inflated to the field where they were put into play.
For a quick refresher course in the physics involved, check out this Khan Academy video lesson on "Gases and Kinetic Molecular Theory."
Not everyone agreed with Belichick, and eventually physicists and mathematicians weighed in. Despite the fact that 2 plus 2 still equals 4, starting assumptions can affect the outcome of the calculations. Here's a fact-checking summary of the debate, which ultimately concludes that Belichik's claim is "mostly true."
Enjoy the game. And if you're not a football fan, you can still enjoy the commercials.