Tweak queen values for midgame and endgame

Queen midgame value: -1%
Queen endgame value: +1%

This patch failed STC, but was exceptionally tested at LTC,
where it passed two independant SPRT tests with bounds [0..4]:

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 20651 W: 3191 L: 2980 D: 14480
http://tests.stockfishchess.org/tests/view/5ab73faa0ebc5902932cbdca

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 89111 W: 13647 L: 13233 D: 62231
http://tests.stockfishchess.org/tests/view/5ab8c0e50ebc5902932cbeae

See https://github.com/official-stockfish/Stockfish/pull/1511
for the discussion of this patch.

How to continue from there?
• there is probably some more Elo gains to get from the tuning
of the queen value.

Bench: 5460229

diff --git a/src/types.h b/src/types.h
index 2cf52ef123ef9694d9aca8772ed4b9f0183295b8..2fb8fe7ba9e1a250fd5a2a7e92a929d8346824f4 100644 (file)
--- a/src/types.h
+++ b/src/types.h
@@ -187,7 +187,7 @@ enum Value : int {
   KnightValueMg = 764,   KnightValueEg = 848,
   BishopValueMg = 826,   BishopValueEg = 891,
   RookValueMg   = 1282,  RookValueEg   = 1373,
-  QueenValueMg  = 2526,  QueenValueEg  = 2646,
+  QueenValueMg  = 2500,  QueenValueEg  = 2670,
 
   MidgameLimit  = 15258, EndgameLimit  = 3915
 };