crafty question

[Cardoso]

Hi,
I noticed that in iterate.c crafty doesn't allways start iterating with 1 ply depth.
It can start with iteration depth 1 plus the last pv depth.
Will this allways be the case? That is will it allways do that everytime it searches a move?
If it would allways start with 1 ply depth would that be wrong?
In what cases will it start with iteration depth = 1 ?
When we start a new game?
When we setup a position?

best regards,
Alvaro

[Aleks Peshkov]

I am not connected with Crafty in any way, but can try to give a quick answer.

Code: Select all

      shared->iteration_depth = 1;
      if (last_pv.pathd > 1)
        shared->iteration_depth = last_pv.pathd + 1; 

Crafty store PV from previous search, if it got an opponent move that predicted by last PV, Crafty can continue deepening from the place it stopped before. This can happen regardless pondering mode on or off.

[bob]

Hi,
I noticed that in iterate.c crafty doesn't allways start iterating with 1 ply depth.
It can start with iteration depth 1 plus the last pv depth.
Will this allways be the case? That is will it allways do that everytime it searches a move?
If it would allways start with 1 ply depth would that be wrong?
In what cases will it start with iteration depth = 1 ?
When we start a new game?
When we setup a position?

best regards,
Alvaro

Think about it for a minute. You complete a 14 ply search, and play the first move, and on a ponder search, you assume your opponent plays the second move. Leaving you 12 plies left of the original search. Why repeat the first twelve plies again? So it starts at 13 and goes forward...

On a mis-predicted search, it always starts at ply=1 of course...