Increase the mg->eg gradient for the PawnlessFlank malus

miguel-l · snicolet · commit c08e05b494d5 · 2018-07-28T07:34:37.000+02:00
Just a change of value to S(19, 84). Also somewhat of a follow up to the recent tweak in definition of KingFlank. I tried a lot of other values before this, increasing and decreasing but with little success, and before giving up I wanted to try tweaking the middlegame and endgame values in the opposite directions. I guess this is somewhat lucky. STC: LLR: 2.94 (-2.94,2.94) [0.00,4.00] Total: 67685 W: 15399 L: 14963 D: 37323 http://tests.stockfishchess.org/tests/view/5b5b5ae80ebc5902bdb8e4f8 LTC: (Also thanks to Stephane Nicolet) LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 54635 W: 9505 L: 9172 D: 35958 http://tests.stockfishchess.org/tests/view/5b5b78f20ebc5902bdb8ece5 Closes #1714 Bench: 4883742
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
@@ -165,7 +165,7 @@ namespace {
   constexpr Score LongDiagonalBishop = S( 22,  0);
   constexpr Score MinorBehindPawn    = S( 16,  0);
   constexpr Score Overload           = S( 13,  6);
-  constexpr Score PawnlessFlank      = S( 20, 80);
+  constexpr Score PawnlessFlank      = S( 19, 84);
   constexpr Score RookOnPawn         = S(  8, 24);
   constexpr Score SliderOnQueen      = S( 42, 21);
   constexpr Score ThreatByKing       = S( 23, 76);
