Permanent brain

In turn-based games, permanent brain (also called pondering) is the act of thinking during the opponent's turn.

The strength of chess programs depends very much on the amount of time allocated for calculating.

If the opponent's move has been guessed correctly, then the program continues to calculate.

For example, if the program guesses 25% of the opponent's moves correctly, the use of pondering is on average equivalent to increasing the normal calculating time by a factor of 1.25.

For this reason, chess GUIs have an option to turn the permanent brain off.