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How Systems Engineering Could Have Spiked the Patriots' Deflated Footballs

by Christine Kowalski | May 07, 2015

by Heidi Hahn & Patrick Hale

Deflategate. When an incident has a colloquial nickname, you know it’s a big deal. At the least, it’s an issue of contention and something to be investigated further.

Investigations are not new to the NFL, but what makes “Deflategate” different is that it is an issue that could have been prevented. It was not tied to personal conduct or rule interpretation, but a simple measurement of air pressure.

What if the NFL had taken a systems engineering approach to inflation procedures?

Within any industry, systems engineering focuses on ensuring that the “pieces” work together to achieve desired results. It is a holistic-yet-meticulous look at each component.

Systems engineering is often referenced in relation to defense or science projects, but it is used in everything from product manufacturing, human resources, hospitals, cyber security to yes, sports like football.

First, a recap of the NFL’s current inflation requirements: For any football game, each team will provide “primary” balls and may provide “backup” balls, depending on the circumstances. Additional footballs, exclusively for kicking, are shipped directly from the manufacturer of all game balls (Wilson) to the referee at the stadium.

All game balls have NFL rule book specifications for brand, materials, evenness, shape, size and weight. Now, for the point of contention: The balls must be inflated to 12.5-13.5 air pressure per square inch. Each team is responsible for inflating their own balls to the specified requirements. The referees are in charge of inflating the kicking footballs and inspecting all balls prior to play.

In the New England Patriots vs. Indianapolis Colts’ playoff game, at half time, one of the referees found 10 of the Patriots’ footballs to be underinflated by one to two pounds; the pressure of the Colts’ footballs remained on point.

While the just-released “Ted Wells report” on the matter, explains what most likely occurred in this case, we can look at how to strengthen the process so this is less likely to happen again.

When a systems engineer looks at a requirement (in this case, the ball inflation requirement), he immediately asks: How can this requirement be verified? How is performance measured? What tests must be conducted to measure performance? What is the plan for documenting test results and for independently confirming the demonstrated performance? 

According to the NFL rule book, "The Referee shall be the sole judge as to whether all balls offered for play comply with the[se] specifications." So far, so good – the referee is an independent entity charged with confirming compliance. Unfortunately, there is no guidance in the rule book about what tests the referee should perform to confirm the required inflation pressure. It only states that the home team must provide the referee a pump to use; no mention is made of whether the pump must be calibrated.

The guidelines also do not explain what evidence must be kept to indicate that the balls passed testing. Instead, the rules seem to imply that the referee visually confirms that the ball is a “'Wilson,' hand selected, bearing the signature of the Commissioner of the League" and only seeks confirmation that the ball meets specs if there is some reason to be suspicious that it does not.

Furthermore, referee confirmation that balls meet the specifications can take place as much as 2.25 hours before game time. This seems more than enough time to permit a slow leak (accidental or intentionally made) to deflate balls below the specified inflation threshold – as is suspected to be the case in Deflategate.

A solid systems engineering test plan would include:

  • Leak testing to ensure that balls that met spec at test time would still meet spec at game time


  • Regulated testing conditions – All testing should be in field conditions, recognizing that pressure may change with the weather


  • Independent oversight of tested footballs until the start of each game, which the NFL is supposed to already practice: “[T]he balls shall remain under the supervision of the Referee until they are delivered to the ball attendant just prior to the start of the game"


  • Spot-checking of balls during the game, with the frequency and rigor of spot-checks depending on the team’s record of violating said requirements

Would using a systems approach to ball specifications have been fool-proof in preventing someone from intentionally deflating the balls? No – a bad actor could still deflate the balls after the game had started. 

However, with a rigorously followed systems engineering plan, Deflategate may have never entered our vocabulary.

Heidi Ann Hahn is director-at-large and past president of the International Council on Systems Engineering (INCOSE), Enchantment Chapter and senior executive advisor to the associate director for engineering sciences at Los Alamos National Laboratory in New Mexico, where she is responsible for engineering capability development.

Patrick Hale is the INCOSE’s chair of nominations and elections and secretary of the INCOSE Foundation, as well as the executive director, SDM (System Design Management) Fellows Program at Massachusetts Institute of Technology. He is an avid football fan.