The purpose of this study was to compare the visual search behaviors of experienced basketball players with those of novices as they anticipated the success of a free throw. In basketball, the accurate judgment of the result of a free throw at an early time is an important factor in both performing the next play for the players and in deciding team tactics for coaches. The subjects were twelve experienced male basketball players and twelve novice counterparts. The task was to anticipate the success of free throws by responding verbally with IN , OUT or Uncertain while viewing randomized successful / unsuccessful video-based models of free throws. The video was captured from a position to the side of the shooter s shooting arm and perpendicular to the plane of the intended motion of the ball. The stimuli were temporally occluded after the ball released the shooter s hand and before the ball reached the goal. In addition, the participants visual search behaviors were acquired by using an eye movement tracking system. The results indicated that experienced players were able to anticipate a successful free throw earlier and more accurately than could the novices. Experienced players had an effective strategy to anticipate the result of free throws that was based on not only the ball s trajectory but also the use of shooter s coordinated motions as advanced cues for predicting the success of a free throw before the release of the ball. The experienced players viewing points were distributed on the shooter s lower body until the execution phase and then on the shooter s shooting arms before ball release. This effective visual search behavior is therefore one of the most important factors in improving accurate judgment at an early time.

The aim of this study was to examine visual search behavior of experienced basketball players when they rebound a basketball by using an eye-movement registration system. In basketball games, the possession of the rebounding ball provides one of the most important statistical data needed to win games. In order to get the rebounding ball, the player is required both to perceive temporal and spatial information through a complex visual field and to react to an opponent player immediately. Therefore, the seven male subjects' experimental task was to block, or so called "box-out," the opponent offensive player under 3 randomized tactical plays in basketball 3-on-3 situations. Subjects' athletic careers ranged from 8 to 12 years （mean ± SD : 9.70 ± 1.50 years） . A subject, a defensive player, was fitted with an eye-tracking device （EMR-9, NAC Inc.） to acquire his viewing point for the detection of visual search behaviors.Subjects' kinematic data was also captured by 3 video cameras （S21, CANON, 60Hz） . The results showed that experienced players could react to the opponent player before the shooter's ball release timing quickly, almost without viewing the shooter. Experienced players showed constant fixations, fixation duration and fixation locations before the shooter released the ball, and the distribution of experienced players' viewing points was set at a spatial area between the shooter and the opponent player under 3 tactical plays. These results indicated that experienced players utilized the properties of an ambient vision system immediately for receiving visual information broadly in order to coordinate their actions ahead of the shooter and the opponent player action under the tactical situation. An effective visual search behavior is therefore an