Don't compensate TT for evaluation drift
authorMarco Costalba <mcostalba@gmail.com>
Fri, 18 Sep 2009 10:12:22 +0000 (12:12 +0200)
committerMarco Costalba <mcostalba@gmail.com>
Sat, 19 Sep 2009 11:52:57 +0000 (12:52 +0100)
It seems that it works better without compensation
of drifted value when saving static evaluation in TT.

After 818 games at 1+0

Mod vs Orig +217 =429 -172 52.75%  431.5/818  +19 ELO

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
src/search.cpp

index 7bc90b143d10b85a94ff0a4cbf9f214e9d0b3525..ac4d85b69996eb7abadda3cf61fcd9d50ec39cf7 100644 (file)
@@ -1556,7 +1556,7 @@ namespace {
     {
         // Store the score to avoid a future costly evaluation() call
         if (!isCheck && !tte && ei.futilityMargin == 0)
-            TT.store(pos.get_key(), bestValue - ply, VALUE_TYPE_EVAL, Depth(-127*OnePly), MOVE_NONE);
+            TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EVAL, Depth(-127*OnePly), MOVE_NONE);
 
         return bestValue;
     }