simplify razoring

Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 93056 W: 24215 L: 24054 D: 44787
Ptnml(0-2): 364, 11085, 23470, 11244, 365
https://tests.stockfishchess.org/tests/view/67883a5d3b8f206a2696b804

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 66564 W: 16971 L: 16794 D: 32799
Ptnml(0-2): 56, 7403, 18192, 7570, 61
https://tests.stockfishchess.org/tests/view/6789ffa78082388fa0cbfe95

closes https://github.com/official-stockfish/Stockfish/pull/5788

bench 1500649
This commit is contained in:
Shawn Xu
2025-01-15 14:44:01 -08:00
committed by Joost VandeVondele
parent 132b90df04
commit ccbd060b01
+2 -3
View File
@@ -784,11 +784,10 @@ Value Search::Worker::search(
}
// Step 7. Razoring (~1 Elo)
// If eval is really low, check with qsearch if we can exceed alpha. If the
// search suggests we cannot exceed alpha, return a speculative fail low.
// If eval is really low, skip search entirely and return the qsearch value.
// For PvNodes, we must have a guard against mates being returned.
if (!PvNode && eval < alpha - 462 - 297 * depth * depth)
return qsearch<NonPV>(pos, ss, alpha - 1, alpha);
return qsearch<NonPV>(pos, ss, alpha, beta);
// Step 8. Futility pruning: child node (~40 Elo)
// The depth condition is important for mate finding.