Do lmr for more captures

Vizvezdenec · snicolet · commit 3f4191392c18 · 2019-11-21T09:52:13.000+01:00
Based on machinery introduced by vondele. Logic behind patch if relatively simple - if we reduce less with high hit rate of transposition table somewhat logical is to reduce more with low hit rate. For example enable all captures for LMR. Threshold 0.375 is arbitrary and can be tweaked :) STC http://tests.stockfishchess.org/tests/view/5dd4d51df531e81cf278eaac LLR: 2.97 (-2.94,2.94) [-1.50,4.50] Total: 16495 W: 3591 L: 3434 D: 9470 LTC http://tests.stockfishchess.org/tests/view/5dd52265f531e81cf278eace LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 23598 W: 3956 L: 3716 D: 15926 Closes #2420 Bench: 5067870
diff --git a/src/search.cpp b/src/search.cpp
@@ -1084,7 +1084,8 @@ namespace {
           && (  !captureOrPromotion
               || moveCountPruning
               || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
-              || cutNode))
+              || cutNode
+              || thisThread->ttHitAverage < 384 * ttHitAverageResolution * ttHitAverageWindow / 1024))
       {
           Depth r = reduction(improving, depth, moveCount);
 

Original file line number	Diff line number	Diff line change
`@@ -1084,7 +1084,8 @@ namespace {`
`1084`	`1084`	`&& ( !captureOrPromotion`
`1085`	`1085`	`\|\| moveCountPruning`
`1086`	`1086`	`\|\| ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha`
`1087`		`- \|\| cutNode))`
	`1087`	`+ \|\| cutNode`
	`1088`	`+ \|\| thisThread->ttHitAverage < 384 * ttHitAverageResolution * ttHitAverageWindow / 1024))`
`1088`	`1089`	`{`
`1089`	`1090`	`Depth r = reduction(improving, depth, moveCount);`
`1090`	`1091`