From: VoyagerOne <excelgeek@gmail.com>
Date: Mon, 3 Apr 2017 03:31:52 +0000 (-0700)
Subject: Don't update TT at excluded move ply
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=ebe021f6a5da63cf0e31da89d4c21e9b5f673fcd

Don't update TT at excluded move ply

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 38906 W: 7125 L: 6835 D: 24946

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 28600 W: 3752 L: 3543 D: 21305

Bench:  6861050

Closes #1048
---

diff --git a/src/search.cpp b/src/search.cpp
index 7029ae03..d555b62e 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1125,10 +1125,11 @@ moves_loop: // When in check search starts from here
              && cm_ok)
         update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth));
 
-    tte->save(posKey, value_to_tt(bestValue, ss->ply),
-              bestValue >= beta ? BOUND_LOWER :
-              PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
-              depth, bestMove, ss->staticEval, TT.generation());
+    if(!excludedMove)
+        tte->save(posKey, value_to_tt(bestValue, ss->ply),
+                      bestValue >= beta ? BOUND_LOWER :
+                      PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
+                      depth, bestMove, ss->staticEval, TT.generation());
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);