Armchair commentators take note: when it comes to predicting whether players are going to make a shot, it really does make all the difference if you currently play the sport yourself.
Salvatore Aglioti and colleagues filmed a player attempting to throw a ball into a basketball hoop, sometimes successfully, sometimes not. They then showed portions of the film to elite basketball players, non-playing experts (coaches and journalists) and novices. Rather than being shown in full, the video was paused at various stages of the player's attempt, either before or after he had released the ball, and the participants' task was to say whether or not his attempt would be successful.
The elite players were significantly more accurate at making this prediction than the non-playing experts and the novices, but only for the short duration video clips that finished before the ball had left the player's hand. This shows the elite players were uniquely capable of using the way the ball was handled to judge whether the shot would be successful. By contrast, the non-playing experts and novices displayed the same accuracy as each other, regardless of the video length.
A second study involved the participants predicting whether a basketball shot would be successful, and also involved them making the same prediction for a football shot. This time, as the participants watched the videos, transcranial magnetic stimulation was used to stimulate their motor cortex and recordings of muscle activity were taken from their hands and forearms.
The muscles of the basketball experts - players and non-players - twitched more in response to the basketball videos than they did to the football videos or to a static image of a basketball player. By contrast, the novices showed an equivalent increase in muscle twitching in response to either action video relative to the static image. Crucially, only the elite players showed a distinct burst of muscle activity prior to the release of an ultimately unsuccessful basketball shot. This shows that their hand muscles, but not those of the other participants, were already twitching in anticipation of the ball bouncing free from the basket.
The researchers said their results show "that although mere visual expertise may trigger motor activation during the observation of domain-specific actions, a fine-tuned motor resonance system subtending elite performance develops only as a consequence of extensive motor practice." In other words, armchair expertise is no substitute for time currently spent on the court or field.
Aglioti, S.M., Cesari, P., Romani, M., Urgesi, C. (2008). Action anticipation and motor resonance in elite basketball players. Nature Neuroscience, 11(9), 1109-1116. DOI: 10.1038/nn.2182