Reading Comprehension

Kenny Perry could taste history. He had a two-shot lead with two holes to go at the 2009 Masters - all he had to do was not make any big mistakes and he would become, at 48, the oldest Masters champion in history. For three days at Augusta, he had played the best golf of his life: on the first 70 holes, he made only four bogeys. But then, at the 71st hole, everything started to fall apart.

It began with his approach shot, which sailed left over the green. On the next shot, Perry watched as his chip and run went horribly awry and the ball raced downhill, past the hole and off the green. The crowd gasped. Perry was lucky to double-putt for a bogey, his first in 22 holes.

On the final hole, the tee shot that looked straight ended up twisting left and landing in a bunker. He then short-sided himself on the green, so that the ball came to rest on a treacherous downhill slope. His next shot got him within 15ft of the hole, and putting for the championship. Perry's face was etched with anxiety. He took out his plumb-bob - a tool that helps golfers determine the break of the green - and tried to measure the subtle curve of the grass. Then he measured again. And again. It's as if Perry no longer trusted his eyes or his instincts. He missed the putt.

The play-off didn't go much better. At the first hole, after a solid drive, Perry's next shot went far right and landed in thick grass. He needed a masterful stroke just to eke out par. And then, on the second extra hole, he unravelled. From the fairway he hit an ugly hook and the ball landed with a thud in the pine trees. Perry looked to be on the verge of tears: he knew he had just lost the Masters. It was not quite a Van de Velde moment - named after the Frenchman who squandered the 1999 Open - but it was not far off.

The next day Perry was stoic. "Great players make it happen," he said. "Your average players don't. And that's the way it is." In other words, the dividing line between winning and disappointment isn't about technique or athleticism or talent. It's about performing under pressure, hitting the shots when they matter most.

We call such failures "choking", if only because a person frayed by pressure might as well not have oxygen. What makes choking so morbidly fascinating is that the performers are incapacitated by their own thoughts. Perry, for example, was so worried about not making a mistake on the 17th that he played a disastrous chip. His mind sabotaged itself.

Scientists have begun to uncover the causes of choking, diagnosing the particular mental differences that allow some people to succeed while others wither in the spotlight. Although it might seem like an amorphous category of failure, their work has revealed that choking is triggered by a specific mental mistake: thinking too much.

The sequence of events typically goes like this: when people get nervous about performing, they become self-conscious. They start to fixate on themselves, trying to make sure that they don't make any mistakes. This can be lethal for a performer. The bowler concentrates too much on his action and loses control of the ball. The footballer misses the penalty by a mile. In each instance, the natural fluidity of performance is lost; the grace of talent disappears.

Sian Beilock, a professor of psychology at the University of Chicago, has helped illuminate the anatomy of choking. She uses golf as her experimental paradigm. When people are learning how to putt, it can seem daunting. There are just so many things to think about. Golfers need to assess the lay of the green, calculate the line of the ball, and get a feel for the grain of the turf. Then they have to monitor their putting motion and make sure that they hit the ball with a smooth, straight stroke. For an inexperienced player, a golf putt can seem unbearably hard, like a life-sized trigonometry problem.

But the mental exertion pays off, at least at first. Beilock has shown that novices hit better putts when they consciously reflect on their actions. The more time they spend thinking about the putt, the more likely they are to hole the ball. By concentrating on their game, by paying attention to the mechanics of their stroke, they can avoid beginner's mistakes.

A little experience, however, changes everything. After golfers have learned how to putt - once they have memorised the necessary movements - analysing the stroke is a waste of time. The brain already knows what to do. It automatically computes the slope of the green, settles on the best putting angle, and decides how hard to hit the ball. Bradley Hatfield, a professor of kinesiology and psychology at the University of Maryland, has monitored the brain wave activity of expert athletes during performance. (Because the subjects have to wear a bulky plastic cap full of electrodes, Hatfield can only study golfers, archers and Olympic rifle shooters.) While the brain waves of beginners show lots of erratic spikes and haphazard rhythms - this is the neural signature of a mind that is humming with conscious thoughts - the minds of expert athletes look strangely serene. When they are performing, they exhibit a rare mental tranquility, as their brain deliberately ignores interruptions from the outside world. This is neurological evidence, Hatfield says, of "the zone", that trance-like mindset which allows experts to perform at peak levels. (As the corporate motto says, the best athletes don't think: they just do it.)

Beilock's data further demonstrate the benefits of relying on the automatic brain when playing a familiar sport. She found that when experienced golfers are forced to think about their putts, they hit significantly worse shots. All those conscious thoughts erase their years of practice. "We bring expert golfers into our lab, we tell them to pay attention to a particular part of their swing, and they just screw up," Beilock says. "When you are at a high level, your skills become somewhat automated. You don't need to pay attention to every step in what you're doing."

This is what happens when people "choke". The part of their brain that monitors their behaviour starts to interfere with actions that are normally made without thinking. Performers begin second guessing skills that they have honed through years of practice. The worst part about choking is that it tends to spiral. The failures build upon each other, so a stressful situation is made more stressful.