Michael Schulder
CNN Senior Executive Producer

Remember how John McEnroe used to go ballistic over what he thought were bad calls by referees? Youtube has a beautiful selection. (click here, and here, and here.) Perhaps a new study in the journal Current Biology will provide McEnroe some vindication. The study examines wrong calls by tennis referees as a way to illustrate the way our brain sometimes plays tricks on us – all of us.

You’ve got to love the name of the study. “Perceptual Mislocalization Of Bouncing Balls By Professional Tennis Referees.” In other words, ‘Refs Make Mistakes.’ The news though is what kind of mistakes they make. Would you think they’re more likely to call an in ball out, or an out ball in? The answer is below. First, a short lesson on the amazing computing power of the brain from the study’s author. His name is David Whitney of The Center for Mind and Brain at The University of California, Davis.

Your Brain is Slower Than The Speed of Light

Professor Whitney explains the brain is a bit sluggish. Just a bit. It works fast but not as fast as the speed of light. So if you’re watching a moving ball, for example, when the ball’s image hits your retina the brain takes about a tenth of a second to process the image. During that tenth of a second “our brain processes billions of bits of information and boils them down to the few most important bits. If the brain couldn’t do that, explains Professor Whitney, “we’d all be overwhelmed by information.” So the brain, unbeknownst to us, makes these instant predictions about where objects are going to be that fraction of a second after the image hits our eyes. Dr. Whitney calls it a brain shortcut. And it usually works. But sometimes the brain tricks us into seeing something the wrong way. That’s what the studies in Professor Whitney’s lab tell us.

So one day, in 2007, Professor Whitney was relaxing, watching Wimbledon on his T.V., when a player challenged a call. For the first time, Whitney saw the new type of super-close up camera that professional tennis now uses to decide whether a disputed call is right or wrong. For Whitney, it was a great opportunity to test his lab observations in real life sports.

Whitney and his team analyzed thousands of points, including 83 calls challenged by a player and found to be wrong. Of the 83 mistakes by the refs, 70 of them were balls the refs called out but were actually in. Only 13 were out balls mistakenly called in. Why the difference? Because of a little-known but well-established fact that, as Professor Whitney puts it, “the human brain misperceives moving objects as shifting in the direction of their motion.” In that tenth of a second between the time the image of the moving ball hits our retina and the brain does its computations, once in a while the brain gets it slightly wrong.

As a result of his Wimbledon analysis - Professor Whitney now recommends that players ‘MAXIMIZE THEIR CHALLENGES” on balls called out that the player thinks are in. But it’s not a good idea to challenge when the ref calls a ball in when you think it’s out. That’s a trick the mind hardly ever plays. And even if you think McEnroe is now vindicated, please, watch your manners.

Finally, here’s the advantage of working at CNN. I had one of the nation’s foremost experts on the eye/brain connection on the phone and he’s just finished a study on the sport I love to play. Here was my opportunity to get a lifetime of competitive advantage. Given this tenth of a second lag between what my eye sees and what my brain registers, how can I use that insight to improve my tennis game and beat the heck out of my opponents.

“I don’t know” Professor Whitney told me. “I’m a bad tennis player.”