The physics of flopping: SMU researcher studies mechanics of NBA fakery

The Koyal Group InfoMag

Was it a flop or not?

Last summer, Dallas Mavericks owner Mark Cuban gave Southern Methodist University more than $100,000 to try to answer that question scientifically. On Thursday, SMU biomechanics expert Peter Weyand demonstrated the early stages of his flopping research to a small group of journalists.

Flopping is when an athlete fakes a fall to trick referees into calling a foul on an opponent. The behavior is prevalent in sports such as basketball and soccer.

It’s an especially sore point with fans.

“In regular life, people tend to dislike dishonest people, and the same thing goes for basketball,” said Jeff Lenchiner, editor of the NBA news site InsideHoops.com. “It’s dishonesty expressed physically, and it’s considered an insult to the game.”

In one compilation of flops posted to YouTube involving Manu Ginobili of the San Antonio Spurs, an outraged spectator calls the behavior “a disease” and a mark of cowardice, “bad sportsmanship and horrible acting.”

Flopping also costs players money. Last year, the National Basketball Association cracked down on the practice. Players now receive a warning after their first flop, followed by a series of escalating fines, from $5,000 for two flops to $30,000 for five violations.

Weyand says there is plenty of good science that can come from studying flopping. “This is uncharted territory,” he says. Scientists lack even a basic understanding of how much force is required to topple someone.

That is one of the experiments Weyand demonstrated Thursday. D’Marquis Allen, an SMU sophomore, stood on a treadmill-like platform. Wearing black spandex shorts, a black cycling T-shirt and reflective sensors stuck to his skin, he braced himself for a shove. Soon a lab volunteer pushed him in the chest with a device called a “flop-buster”: a padded yellow bar embedded with sensors. Allen took several steps back.

“That was definitely a foul,” Weyand said later, after measuring the force of the collision.

The research team was surrounded by gadgets that will help it measure the mechanics of basketball collisions. High-speed cameras recorded motion in three-dimensional space. Force plates beneath the platform on which Allen was standing marked his center of gravity. And motion sensors measured Allen’s position, velocity and acceleration.

The goal: to help officials tell flop from foul by simply looking at a video.

“I feel strongly about introducing science and data to situations in business and sports where there previously had been none,” Cuban said by email. “I love to challenge conventional wisdom with” research.

But at this stage, it’s unclear whether flopping can be measured scientifically.

“I have doubts that a monitoring system could distinguish flops from legitimate falls with an accuracy approaching [or exceeding] the opinion of a human observer,” Steve Robinovitch, a biomechanics expert at Simon Fraser University in British Columbia, Canada, wrote in an email.

There may be too many variables, he said, from whether a player is expecting the collision, to his precise posture at the time, to the location where the force is applied.

That’s why Weyand is starting small. For now, he is studying collisions between a moving offensive player and a stationary defensive player. In the second phase, set to take place this summer, he plans to move the experiment into a basketball-like setting to test the forces involved when two moving players collide.

The project is set to end in August, when Weyand’s team must report findings to Cuban’s company Radical Hoops, which funded the research. He then plans to submit his findings to a peer-reviewed journal.

“The real value in these studies is looking toward injury prevention analytics — to predict injury risk factors,” said Gregory Myer, a sports medicine expert at Cincinnati Children’s Hospital Medical Center. “And that’s where the focus really has the big payoff.”