Monday, 11 February 2013

The A - Z of Sports Vision - Heuristics

A batsman slogs the ball into the outfield. A fielder has to run round and judge where and when the ball is going to land so that he can position himself to take the catch. How does he do it? How does he work out all the different permutations of ball speed, height and distance in just a second or two? The answer is he doesn't: he uses a heuristic (although he probably doesn't know he’s using it). A heuristic is a kind of rule-of-thumb that enables people to solve problems and make judgements when there is little time to do so. In the case of the fielder, the trick is to adjust his speed so that the angle of gaze (the angle between the eye and the ball, relative to the ground) remains constant. This is the same method by which a dog might catch a Frisbee (McLeod & Dienes, 1996). A footballer at the edge of the penalty area may have the choice of passing or taking a shot. Does she choose the first thing that comes to mind (“take-the-first” heuristic)? Investigating teenage handball players, Johnson & Raab (2003) found support for this idea. Players were shown a situation on video, and had to describe the first option that they thought of. They were then given another 45 seconds to view the picture before being asked to select the best option. In 60% of cases, they chose the first option they thought of as being the best. Interestingly, having longer to think about it didn't improve the quality of the players’ final choices. Those that changed their minds would have been better off sticking to their original thought. This is because the first choice isn't just a random thought. For elite athletes, it’s embedded in their long-term memory through countless hours of practice. It’s like a simple “If…then” programme (If you see this, then do that). This is why the best players make the game look easy. Because for them, it does become a simple game. David Donner