Even if you aren’t among the third of Americans who will sit down to watch the Super Bowl this Sunday, if you follow the news you are undoubtedly familiar with ‘Deflategate,’ the scandal surrounding under-inflated footballs that cast a dark cloud over the New England Patriots’ win over the Indianapolis Colts over a week ago.
Ever since, sports analysts and scientists alike have been weighing in on the controversy, offering commentary on everything from how the pressure change could have occurred in the first place, to whether or not the difference in pressure really could have given the Patriots an advantage. Now, Popular Science has joined up with engineering software vendor ANSYS to put the deflategate theories to the test.
The central argument in most criticisms over the deflated footballs is that a less inflated ball is easier to grip, and thus easier to pass and catch. But does that really hold true?
Using ANSYS’ new AIM multiphysics simulation environment, the team analyzed the two pressures that were measured at the Colts-Patriots game: the designated inflation of 12.5 psi, and the recorded inflation of Patriots footballs, 10.5 psi.
To measure the effect of the pressures on grip, the team simulated the pressure points that a quarterback’s hand would exert on the outside of the football during a throw, to see if the 2 psi difference would provide any benefit in terms of grip.
So could the deflated ball offer an edge in terms of grip? From the simulation’s point of view, not really. The tests found that the difference in the ball’s ability to deform – and thus conform to the thrower or catcher’s hand – was less than 1 mm. This has a negligible effect on the squeeze imprint (whether in the hands of the quarterback or receiver), which remains at about 5 mm.
And as Barry Christenson, director of product management for ANSYS and author of the blog post detailing the simulation, adds, “In the world of players wearing tacky, rubberized football gloves, the ‘softness’ difference is negligible.”
But if grip wasn’t the deciding factor of the game, what was it? To find out, the team modeled a thrown football to study whether differences in spiral tightness could have been the secret ingredient to the Patriots’ success.
In short? Absolutely. The simulation showed that if the spiral’s axis is off by even 10 degrees, giving it a slight wobble, it could take several yards off a pass. However, once again, the 2 psi difference was not the culprit; the study found that both 10.5 and 12.5 psi balls had the same shape, air flow, and aerodynamics. Meaning that either way, the onus is on the quarterback to make sure the ball flies right.