kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-30 08:43:09 +00:00
Code Issues Releases Wiki Activity

Reintroduce null move dynamic reduction

Browse source 
Test extension of LMR horizon to 3 plies alone, without
touching null move search. To keep the patch minimal we still
don't change LMR horizon in PV search. This will be the object
of the next patch.

Result seems good after 998 games:

Mod vs Orig  +252/=518/-228 51.20%  511.0/998 +8 ELO

So dynamic null move reduction seems a bit stronger then
fixed reduction even with LMR horizon set to 3.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2009-07-16 07:05:54 +01:00
parent fe523b2d18
commit 620cfbb676
1 changed files with 3 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
src/search.cpp
View file

@ -1243,8 +1243,9 @@ namespace {
StateInfo st;
pos.do_null_move(st);
int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction
Value nullValue = -search(pos, ss, -(beta-1), depth-4*OnePly, ply+1, false, threadID);
Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
pos.undo_null_move();
@ -1363,7 +1364,7 @@ namespace {
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
if ( depth >= (ss[ply-1].currentMove == MOVE_NULL ? 3 : 2) * OnePly
if ( depth >= 3*OnePly
&& moveCount >= LMRNonPVMoves
&& !dangerous
&& !moveIsCapture