hitting the ball

In most sports, which involve hitting a ball, the coach's advice is to 'keep your eye on the ball'. However, when a ball moves very fast, this strategy may not always be possible or even appropriate. And now a fascinating new study carried out at Oxford University has revealed that, in fact, cricket batsmen do not watch the ball continuously but operate a distinct eye movement strategy of viewing it at crucial moments during its flight.

Researchers Michael Land and Peter McLeod measured the eye movements and field of gaze during batting of three batsmen with head-mounted eye cameras as they faced balls delivered at 25m per second from a bowling machine. The batsmen, selected for their widely varying abilities were: Mark, a professional cricketer who has opened the batting for Warwickshire; Charlie, a successful amateur who plays Minor Counties cricket for Oxfordshire, and Richard, described as an 'enthusiastic but incompetent amateur', who plays low-level club cricket.

Despite their widely varying skills, Mark, Charlie and Richard's overall visual strategy was observed to be similar: they fixed on the ball as it was delivered, switched their gaze to the anticipated bounce point before the ball got there, then tracked its trajectory for 100-200 milliseconds (MS) after the bounce.

However, within this common strategy, there were differences that seemed to reflect their abilities. Mark, the best batsmen, used more pre-bounce pursuit tracking than Charlie or Richard. Richard, the least-skilled batsman, was slower to respond to the appearance of the ball and to anticipate the bounce point, and the researchers concluded that he would have been unable to manage faster deliveries. By comparison, even with very short balls, Mark and Charlie reached the bounce point with their eyes 100m before the ball.

'In comparing the good (Mark and Charlie) and the poor (Richard) batsmen,' comment the researchers, 'we suggest that the main aspect of oculo-motor behaviour that is related to batting performance is the speed and variability of the initial saccade [a brief rapid eye movement between fixation points].

'The skill difference between the expert batsman (Mark) and the good batsman (Charlie) is possibly due to Mark's subtle combination of pursuit tracking and saccadic movement as he locates the bounce point. There seemed to be no systematic differences in the way the three batsmen tracked the ball after the bounce.'

Nat Neurosci 2000 Dec;3(12):1340-5

Isabel Walker