Rook tweaks in evaluation

Some small changes in evaluation to try to convince Stockfish to centralize
her rooks more in middle game and avoid trapping them in the corners. Joint
work by SFisGOD and snicolet.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 99826 W: 21895 L: 21341 D: 56590
http://tests.stockfishchess.org/tests/view/5bdc3e280ebc595e0ae277df

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 21467 W: 3541 L: 3322 D: 14604
http://tests.stockfishchess.org/tests/view/5bdc9ff30ebc595e0ae28119

Bench: 3631608

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index daf0c1d74d7b2c1e1b5460b5714852ce94ec9e08..34ec48902cfe9986d5c786e11b92fcdc5efc8566 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -127,7 +127,7 @@ namespace {
 
   // RookOnFile[semiopen/open] contains bonuses for each rook when there is
   // no (friendly) pawn on the rook file.
-  constexpr Score RookOnFile[] = { S(20, 7), S(45, 20) };
+  constexpr Score RookOnFile[] = { S(18, 7), S(44, 20) };
 
   // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
   // which piece type attacks which one. Attacks on lesser pieces which are
@@ -165,13 +165,13 @@ namespace {
   constexpr Score MinorBehindPawn    = S( 16,  0);
   constexpr Score Overload           = S( 13,  6);
   constexpr Score PawnlessFlank      = S( 19, 84);
-  constexpr Score RookOnPawn         = S( 10, 30);
+  constexpr Score RookOnPawn         = S( 10, 29);
   constexpr Score SliderOnQueen      = S( 42, 21);
   constexpr Score ThreatByKing       = S( 22, 78);
   constexpr Score ThreatByPawnPush   = S( 45, 40);
   constexpr Score ThreatByRank       = S( 16,  3);
   constexpr Score ThreatBySafePawn   = S(173,102);
-  constexpr Score TrappedRook        = S( 92,  0);
+  constexpr Score TrappedRook        = S( 96,  5);
   constexpr Score WeakQueen          = S( 50, 10);
   constexpr Score WeakUnopposedPawn  = S( 15, 19);
 

diff --git a/src/psqt.cpp b/src/psqt.cpp
index 934f98986c22ff2b20fcb3b9c1c999ed59dd15b0..c9065cbe37289cad176c4331f18f667ff42a4ba7 100644 (file)
--- a/src/psqt.cpp
+++ b/src/psqt.cpp
@@ -67,7 +67,7 @@ constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
    { S(-47,-55), S( -7,-32), S(-17,-36), S(-29,-17) }
   },
   { // Rook
-   { S(-25, 0), S(-16, 0), S(-16, 0), S(-9, 0) },
+   { S(-25, 0), S(-16, 0), S(-10, 5), S( 6, 5) },
    { S(-21, 0), S( -8, 0), S( -3, 0), S( 0, 0) },
    { S(-21, 0), S( -9, 0), S( -4, 0), S( 2, 0) },
    { S(-22, 0), S( -6, 0), S( -1, 0), S( 2, 0) },