HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-06 10:53:50 +08:00
Code Issues Packages Projects Releases Wiki Activity

Simplify razor changes

Browse Source 
Remove razoring changes from
https://github.com/official-stockfish/Stockfish/pull/5360

The mentioned patch introduced the usage of futility_margin into
razoring alongside a tune to futility_margin. It seems the elo gained in
this patch comes from the tune of futility_margin and not the
introduction of futility_margin to razoring, so simplify it away here.

Passed Non-regression STC:
https://tests.stockfishchess.org/tests/view/66606581c340c8eed7757bc8
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 169056 W: 43922 L: 43848 D: 81286
Ptnml(0-2): 438, 20288, 43034, 20298, 470

Passed Non-regression LTC:
https://tests.stockfishchess.org/tests/view/66607764c340c8eed7757c58
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 157134 W: 39805 L: 39723 D: 77606
Ptnml(0-2): 74, 17444, 43461, 17502, 86

Passed rebased Non-regression LTC:
https://tests.stockfishchess.org/tests/view/6660c696c340c8eed77580c0
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 135984 W: 34427 L: 34324 D: 67233
Ptnml(0-2): 67, 15063, 37615, 15194, 53

closes https://github.com/official-stockfish/Stockfish/pull/5366

Bench: 1150518
This commit is contained in:
rn5f107s2
2024-06-05 18:56:25 +02:00
committed by Disservin
parent 66ed4312f2
commit 5dda4037c7
1 changed files with 6 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
src/search.cpp
View File

@@ -554,7 +554,7 @@ Value Search::Worker::search(
bool givesCheck, improving, priorCapture, opponentWorsening;
bool capture, moveCountPruning, ttCapture;
Piece movedPiece;
int moveCount, captureCount, quietCount, futilityMargin;
int moveCount, captureCount, quietCount;
Bound singularBound;
// Step 1. Initialize node
@@ -762,12 +762,10 @@ Value Search::Worker::search(
opponentWorsening = ss->staticEval + (ss - 1)->staticEval > 2;
futilityMargin = futility_margin(depth, cutNode && !ss->ttHit, improving, opponentWorsening);
// Step 7. Razoring (~1 Elo)
// If eval is really low check with qsearch if it can exceed alpha, if it can't,
// return a fail low.
if (eval < alpha - 465 - futilityMargin * depth * 33 / 32)
if (eval < alpha - 512 - 293 * depth * depth)
{
value = qsearch<NonPV>(pos, ss, alpha - 1, alpha);
if (value < alpha)
@@ -776,7 +774,10 @@ Value Search::Worker::search(
// Step 8. Futility pruning: child node (~40 Elo)
// The depth condition is important for mate finding.
if (!ss->ttPv && depth < 13 && eval - futilityMargin - (ss - 1)->statScore / 263 >= beta
if (!ss->ttPv && depth < 13
&& eval - futility_margin(depth, cutNode && !ss->ttHit, improving, opponentWorsening)
- (ss - 1)->statScore / 263
>= beta
&& eval >= beta && eval < VALUE_TB_WIN_IN_MAX_PLY && (!ttMove || ttCapture))
return beta > VALUE_TB_LOSS_IN_MAX_PLY ? beta + (eval - beta) / 3 : eval;