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The Debunker: Can Fans Distract a Free Throw Shooter?

by Ken Jennings

It's October and, sports fans, basketball is back. The NBA tips off this month, and college ball is just a few weeks away. To celebrate the return of America's greatest invention (even if Dr. James Naismith, who dreamed up the game in 1891, was Canadian-born) we’ve invited Jeopardy! all-star Ken Jennings to join our team. He'll be on the court here all month blowing the whistle on a lot of hoops hoodoo that may fool a lot of fans. Is your basketball knowledge a slam-dunk or an alley-oops?

The Debunker: Can Fans Distract a Free Throw Shooter?

When it comes to participation, baseball fans not named Steve Bartman are pretty much limited to one role: root, root, root for the home team. But in basketball, fans with the right seats often believe they can change the course of the game! If they sit behind the visiting team's backboard, they can attempt to distract free throw shooters as they step to the line. When this practice began decades ago, it was fairly primitive: fans waggling signs or pom-poms or foam noodles in hopes that the resulting sea of motion, viewed through a glass backboard, would brick a few foul shots. But in recent years, the science of free throw distraction has advanced in bizarre and baroque ways. Today, a player attempting a foul shot on the road might be facing fans spinning hypnosis wheels, hoisting a giant 3D-printed puppet, or wearing masks of the foul shooter's own supermodel wife.

The Debunker

As journalist Daniel Engber noted in Slate, the only problem is that none of this stuff actually works. It's easy to compare team foul shooting percentages at home vs. on the road. When Engber ran the numbers back in 2004, free throw accuracy was virtually identical with and without the pom-poms. There were 194 NBA players—almost exactly half the league—who shot better on the road. Engber had a theory that fans in coordinated motion might provide a more nauseating background for foul shooters than random movement, and actually persuaded Mark Cuban to try this tack at Mavericks games for a week in 2005. It didn't work either.

But what about in Tempe, Arizona? Arizona State's famed "Curtain of Distraction" is a cloth mounted on PVC piping that slides back in the stands behind the visitor's' basket to reveal any one of over one hundred surprising tableaux: Village People impersonators, unicorns making out, Michael Phelps in a Speedo wearing all his gold medals. The gimmick now has its own storage room at Wells Fargo Arena, filled with costumes and props. A 2015 New York Times analysis suggests that this kind of very elaborate distraction may, for the first time in basketball history, have made a dent in free throw numbers. The Sun Devils' opponents used to shoot 75% in the second half; in the post-Curtain era they shot 60% percent. But Engber is still skeptical, pointing out that ASU opponents still shoot about the same at the line in the second half (when they're facing the Curtain) as they do in the first half, and that the pre-Curtain numbers may have been anomalously high for some reason. The only way to figure this out for sure might just be Michael Phelps in a unicorn mask.

Quick Quiz: What do magicians call the act of distracting an audience from the workings of a trick, as with a wand or patter?

Ken Jennings is the author of twelve books, most recently Planet Funny and co-hosts the most important podcast in human history, Omnibus. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at or on Twitter as @KenJennings.