kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-29 16:23:09 +00:00
Code Issues Releases Wiki Activity

simplify away quietCheckEvasions pruning

Browse source 
simplifies away the pruning of quiet evasion moves in quiescent search.

Passed STC:
LLR: 2.98 (-2.94,2.94) <-1.75,0.25>
Total: 343520 W: 88356 L: 88470 D: 166694
Ptnml(0-2): 1061, 40073, 89706, 39759, 1161
https://tests.stockfishchess.org/tests/view/663c7ddfc0b75d7f7b980f3b

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 168744 W: 42454 L: 42384 D: 83906
Ptnml(0-2): 75, 18678, 46782, 18776, 61
https://tests.stockfishchess.org/tests/view/663ce34fc0b75d7f7b981ed9

closes https://github.com/official-stockfish/Stockfish/pull/5231

bench 3681552
This commit is contained in:
Shawn Xu 2024-05-09 00:38:43 -07:00 • committed by Joost VandeVondele
parent b8812138e8
commit 540545d127
1 changed files with 0 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
src/search.cpp
View file

@ -1502,8 +1502,6 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory, MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory,
contHist, &thisThread->pawnHistory); contHist, &thisThread->pawnHistory);
int quietCheckEvasions = 0;
// Step 5. Loop through all pseudo-legal moves until no moves remain // Step 5. Loop through all pseudo-legal moves until no moves remain
// or a beta cutoff occurs. // or a beta cutoff occurs.
while ((move = mp.next_move()) != Move::none()) while ((move = mp.next_move()) != Move::none())
@ -1556,12 +1554,6 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
} }
} }
// We prune after the second quiet check evasion move, where being 'in check' is
// implicitly checked through the counter, and being a 'quiet move' apart from
// being a tt move is assumed after an increment because captures are pushed ahead.
if (quietCheckEvasions > 1)
break;
// Continuation history based pruning (~3 Elo) // Continuation history based pruning (~3 Elo)
if (!capture if (!capture
&& (*contHist[0])[pos.moved_piece(move)][move.to_sq()] && (*contHist[0])[pos.moved_piece(move)][move.to_sq()]
@ -1585,8 +1577,6 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
&thisThread &thisThread
->continuationHistory[ss->inCheck][capture][pos.moved_piece(move)][move.to_sq()]; ->continuationHistory[ss->inCheck][capture][pos.moved_piece(move)][move.to_sq()];
quietCheckEvasions += !capture && ss->inCheck;
// Step 7. Make and search the move // Step 7. Make and search the move
thisThread->nodes.fetch_add(1, std::memory_order_relaxed); thisThread->nodes.fetch_add(1, std::memory_order_relaxed);
pos.do_move(move, st, givesCheck); pos.do_move(move, st, givesCheck);