Uncertainty and visual strategies in table tennis

Ball games are characterized by perceptual uncertainty and time-pressure. Of interest is the visual-search pattern carried out when these characteristics change. This is the case in table-tennis situations when comparing a drill situation, when one kind of stroke is constantly repeated, and a match situation, when the stroke is more often unpredictable. We analysed, during play, the visual-search pattern of five expert table tennis players to examine the effect of uncertainty on visual behavior. Direction of gaze was recorded by a video-oculographic recorder (NAC Eye Mark Recorder IV). Analysis showed that (i) visual fixations towards opponent player were only systematic in a match contrary to drill where they occurred less frequently. (ii) Whatever the situation, only the first part of the ball's trajectory was visually tracked. This occurred immediately after the opponent's release of the ball. Nevertheless, visual tracking was more frequent and of longer duration in a match. (iii) Analysis of motor behavior showed that the duration of the movement preparation was longer in a match while the duration of the execution phase was unchanged.