Simplify collection of bad moves for history updates.

1. collect only the first 32 moves searched and ignore the rest. So late bad moves get no further negative history updates.
2. collect now for quiet moves also at most 32 bad moves

STC:
https://tests.stockfishchess.org/tests/view/6517b3aeb3e74811c8af5651
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 51168 W: 13013 L: 12810 D: 25345
Ptnml(0-2): 120, 6006, 13186, 6095, 177

LTC:
https://tests.stockfishchess.org/tests/view/651adafecff46e538ee02734
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 109866 W: 27786 L: 27656 D: 54424
Ptnml(0-2): 52, 11816, 31069, 11942, 54

closes https://github.com/official-stockfish/Stockfish/pull/4818

Bench: 1338617

diff --git a/src/search.cpp b/src/search.cpp
index 5508478862fe1a37f75cd09e9169db8e3836e0dc..f49c23aed6571dcc8a6d024f3f2b813fb08a3290 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -546,7 +546,7 @@ namespace {
     assert(0 < depth && depth < MAX_PLY);
     assert(!(PvNode && cutNode));
 
-    Move pv[MAX_PLY+1], capturesSearched[32], quietsSearched[64];
+    Move pv[MAX_PLY+1], capturesSearched[32], quietsSearched[32];
     StateInfo st;
     ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize);
 
@@ -1328,12 +1328,12 @@ moves_loop: // When in check, search starts here
 
 
       // If the move is worse than some previously searched move, remember it, to update its stats later
-      if (move != bestMove)
+      if (move != bestMove && moveCount <= 32)
       {
-          if (capture && captureCount < 32)
+          if (capture)
               capturesSearched[captureCount++] = move;
 
-          else if (!capture && quietCount < 64)
+          else
               quietsSearched[quietCount++] = move;
       }
     }