# Computer Chess Club Archives

## Messages

### Subject: Re: How much time per move?

Author: Christophe Theron

Date: 12:45:18 03/02/98

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On March 02, 1998 at 15:25:46, Andrew Williams wrote:

>Just a quick question:
>
>How do programmers decide how much time to spend on each move
>when the time controls state that the program has n minutes for
>the whole game?
>

Here is what I do for "KO" time controls (you have a given time to
complete the whole game):

1) Estimate the number of moves to complete the game, based on the
current state of the game. This is not very precise, but if you are at
move 2 you can expect the game to last for 60 more moves, and if you are
deep in the endgame you can say the game will be over in 30 moves or
less.
2) Divide the time left by the number of moves left. You should take a
little margin here, for example dividing by (number_of_moves_left + 1).

This gives you a target time. During the search, allow the program to
continue up to 2 or 3 time this target if it discovers that the score
suddenly drops. That's why I have to keep a margin.

You can also decrease the target time if you are able to determine that
one move is clearly obvious and forced (taking the opponent's queen for
example).

Some programs double the target time for N moves after leaving the
opening book (N=1..4). Because often the programs make the ugliest moves
right after their opening book moves.

Christophe