Wednesday, 5 December 2012

The A - Z of Sports Vision - Deception

One of the main advantages that an elite athlete has over a novice is the ability to anticipate the actions of their opponent. The opponent, however, can try and counter this by adding a deception or disguise into their play. One of the earliest exponents of this kind of deceptive play was Stanley Matthews. He would tap the ball with the inside of his foot to feint in one direction, and then use the outside of his foot to drag the ball past the defender in the opposite direction. The advent of one-day cricket has seen the blossoming of the “slower ball”. This is achieved by changing the grip on the ball so that it comes out of the hand more slowly than the standard delivery but, crucially, the arm speed remains the same which makes it difficult to spot. The best one-day batsmen however, such as Indian wicketkeeper M S Dhoni, are tending to commit to their stroke a little later in response. In squash, Flynn (1996) identified several ways in which a player might deceive his opponent, such as using his body to shield the ball, set up a pattern of play so that the opponent comes to expect the same play again, or adjusting the timing of the swing so that it’s less obvious when the racket will make contact with the ball. There has not been a great deal of research into this area, but Schmidt & Wrisberg (2008) found that when an athlete wants to cause a delay in an opponent’s response, the time between the fake and the real movement should be between 60 and 100ms. If the time is shorter than that, the opponent may ignore the fake movement and react to the intended movement. If the time is longer than 100ms, the opponent may react with only a slight delay which may not be much slower than a normal response. One of the most detailed analyses of the use of deception in sport has been the analysis of the sidestep in rugby by Brault, Bideau, Kulpa & Craig (2012). They found that novice rugby players were more easily misled by movements of the head, upper body and outside foot than experts, who appeared to be more attuned to the angle of the hips, which is a reliable guide to the final running direction. Experts also waited longer before committing themselves in one direction or the other. The authors suggest that deception could be increased if the player wears brightly coloured boots or has contrasting colours on the upper part of their shirt. So maybe those players with gold boots aren't just being flash after all. David Donner