kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-06-28 00:19:50 +00:00
Code Issues Releases Wiki Activity

Do shallower search in case of lmr being not successful enough

Browse source 
In case of a move passing LMR but it results being not too far from
the current best search result produce a full depth search with reduced depth.

Original idea by lonfom169 .

Passed STC:
https://tests.stockfishchess.org/tests/view/6373409b54d69a2f33913fbd
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 169504 W: 45351 L: 44848 D: 79305
Ptnml(0-2): 598, 18853, 45353, 19344, 604

Passed LTC:
https://tests.stockfishchess.org/tests/view/6374c58528e3405283eb8d2d
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 51144 W: 13802 L: 13471 D: 23871
Ptnml(0-2): 19, 4928, 15362, 5229, 34

closes https://github.com/official-stockfish/Stockfish/pull/4230

bench 4277005
This commit is contained in:
Michael Chaly 2022-11-17 18:31:59 +03:00 • committed by Joost VandeVondele
parent 6c1df553fa
commit 219fa2f0a7
1 changed files with 4 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
src/search.cpp
View file

@ -1184,8 +1184,11 @@ moves_loop: // When in check, search starts here
// Do full depth search when reduced LMR search fails high // Do full depth search when reduced LMR search fails high
if (value > alpha && d < newDepth) if (value > alpha && d < newDepth)
{ {
// Adjust full depth search based on LMR results - if result
// was good enough search deeper, if it was bad enough search shallower
const bool doDeeperSearch = value > (alpha + 64 + 11 * (newDepth - d)); const bool doDeeperSearch = value > (alpha + 64 + 11 * (newDepth - d));
value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth + doDeeperSearch, !cutNode); const bool doShallowerSearch = value < bestValue + newDepth;
value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth + doDeeperSearch - doShallowerSearch, !cutNode);
int bonus = value > alpha ? stat_bonus(newDepth) int bonus = value > alpha ? stat_bonus(newDepth)
: -stat_bonus(newDepth); : -stat_bonus(newDepth);