Do more futility pruning

xu-shawn · vondele · commit 035cb146d430 · 2025-11-17T14:03:02.000+01:00
closes official-stockfish#6433 Bench: 2469519
diff --git a/src/search.cpp b/src/search.cpp
@@ -857,7 +857,7 @@ Value Search::Worker::search(
     // The depth condition is important for mate finding.
     {
         auto futility_margin = [&](Depth d) {
-            Value futilityMult = 91 - 21 * !ss->ttHit;
+            Value futilityMult = 81 - 21 * !ss->ttHit;
 
             return futilityMult * d                               //
                  - 2094 * improving * futilityMult / 1024         //

Original file line number	Diff line number	Diff line change
`@@ -857,7 +857,7 @@ Value Search::Worker::search(`
`857`	`857`	`// The depth condition is important for mate finding.`
`858`	`858`	`{`
`859`	`859`	`auto futility_margin = [&](Depth d) {`
`860`		`- Value futilityMult = 91 - 21 * !ss->ttHit;`
	`860`	`+ Value futilityMult = 81 - 21 * !ss->ttHit;`
`861`	`861`
`862`	`862`	`return futilityMult * d //`
`863`	`863`	`- 2094 * improving * futilityMult / 1024 //`