"How does a quarterback think so fast?
We can understand that by looking at other disciplines. Like quarterbacks, radiologists are experts in seeing things quickly. What is invisible to us is obvious to them. They can diagnose a disease after looking at a chest X-ray for a fifth of a second, the time it takes to make a single voluntary eye movement. As they become more trained, they move their eyes less until all they have to do is glance at a few locations for a few moments to find the information they need.
This is called “selective attention.” It is a hallmark of expertise.
Adriaan de Groot, a chess master and psychologist, studied expertise by showing a chess position to players of different ranks. He found that grandmasters evaluated few moves and re-evaluated them less often than other players. One grandmaster evaluated one move twice, then evaluated another and played it. It was the best possible move. This was generally true: Grandmasters never considered moves that were not one of the top five best possible moves. Other players considered moves as poor as twenty-second-best. The less expert the player, the more options they considered, the more evaluations they made, and the worse their eventual move was.
Less thinking led to better solutions. More thinking led to worse solutions. Were grandmasters making their moves by inspiration?
No. Experts do not think less. They think more efficiently. The practiced brain eliminates poor solutions before they reach the conscious mind."
Via Howard Rheingold