A trained athlete’s brain operates at a speed much greater than the brain of an untrained person. In 2001, the Yankees were in an American League playoff game with the Oakland Athletics. Yankee Shortstop Derek Jeter saved the game and the series when he grabbed an errant throw coming in from right field and then gently tossed the ball to catcher Jorge Posada, who tagged the base runner at home plate. To make the play, Jeter had to master both conscious decisions, such as whether to intercept the throw, and unconscious ones, such as how hard to throw the ball. Jeter made these decisions correctly, in an instant.
On August 20, 1974, in a game between the California Angles and the Detroit Tigers, a Nolan Ryan fastball was clocked at 100.9 mph. This means the ball reached home plate in 4-tenths of a second. The unconscious part of a hitter's brain can process the visual data it receives from the eyes and cause the body to swing the bat in less than this time, else it would be impossible for batters to hit the fastball. The conscious mind takes about 5-tenths of second to react to the pitch so, if the batter thinks about hitting the ball, he will always be too late. This is also why a highly trained fighter is able to avoid a punch before being consciously aware of it.
A marksman’s task is easy; he simply points the weapon and fires it, and yet each shot requires many instantaneous decisions, such as how much to shift the aim in response to wind and temperature. Since the shooter does not have perfect control over his body, a slight movement in one part of the body may require many quick adjustments in other parts. Each shot is combination of minor adjustments made by combining previous experiences learned in training with whatever variations are being experienced at the moment.