AEI researchers, Midé engineers put pressure on football’s Deflategate

If you follow American professional football, you’ve probably heard of Deflategate, in which the New England Patriots are alleged to have used underinflated footballs, which many quarterbacks find easier to hold and control in cold or wet weather. This contention was supported by a study (the “Wells report”) by National Football League, which is imposing penalties on the Patriots for cheating.

But now an independent study from the American Enterprise Institute calls into question the NFL findings—as have experiments conducted by engineers at Midé, who used a Thermotron temperature chamber to mimic the on- and off-field conditions under which the footballs in question were tested.

First, as recounted in the Sunday New York Times, Kevin A. Hassett and Stan Veuger of the AEI (who conducted the study along with Joseph W. Sullivan), the Wells report contends that during the first half of play, the pressure of the balls provided and used by the Patriots declined more than that of the balls provided by the Patriots’ opponents (the Colts) in a statistically significant way.

However, Hasset and Veuger write, “…when we analyzed the data provided in the Wells report, we found that the Patriots balls declined by about the expected amount, while the Colts balls declined by less.” They suggest the difference is because 11 Patriots balls were measured at the beginning of halftime in cool field conditions, whereas four Colts balls were measured at the end of halftime after sitting in a warm room.

They recount another problem—one related to calibration. They write, “The NFL official who checked the pressure before the game used some combination of two pressure gauges to measure the Patriots and Colts balls, but it is not known which particular combination.”

They add, “One of the gauges, as the report notes, records pressures that are higher than the other”—leading to the possibility that the Patriots balls may have been inadvertently underinflated at the beginning of the game. You can download the complete AEI report here.

As for Midé—it’s a small company located in Medford, MA, that makes products including QuickPack actuators and SlamSticks; the latter cost-effectively log vibration, temperature, and pressure measurements through sensors. The company also makes bulkhead seals for the U.S. Navy and thermally responsive insulation whose fibers change shape depending on temperature. In their work they make use of Thermotron SM-8 and SM-32 temperature-humidity chambers.

About a week after Deflategate, they did some math and set up an experiment using the SM-32 chamber.

“Even though we are Patriots fans, we wanted to prove the science behind temperature and air pressure,” said Chris Ludlow, Midé’s VP of engineering, in a case study forwarded by Thermotron. “Our reputations as engineers are more important than our loyalty to the Patriots.”

According to the case study, “Two official NFL footballs were placed in the calibrated Thermotron thermal chamber and set at 24°C (75°F)—the approximate temperature when NFL officials tested the footballs about an hour before the game. The first football’s pressure measured 13.4 psi (the high end of the allowed range) and the second was 12.6 psi (the low end of the allowed range, where [Patriots quarterback] Tom Brady prefers it).

“The footballs were then placed back in the chamber and set at the game-time temperature of 10°C (50°F). After 90 minutes each football’s pressure was measured again. The first ball dropped from 13.4 psi to 12.3 psi, and the second ball went from 12.6 psi to 11.5 psi, a significant difference!”

Apart from investigating Deflategate, Ludlow said, “We perform reliability tests to get new technologies into the marketplace. We want to test and identify failures before the product is launched. We don’t have 15 to 20 years to test a new product to make sure it works that long. By performing aggressive environmental testing we can prove that a new product will withstand those rigors.”

Watch a video of Ludlow’s Deflategate experiment here.