Adjust definition of unsafeSquares

and adjust related bonus values. The bonus is now not given whenever
there is an enemy piece in front of the pawn.

Passed STC:
LLR: 2.94 (-2.94,2.94) {-0.25,1.25}
Total: 109472 W: 22097 L: 21673 D: 65702
Ptnml(0-2): 2111, 12800, 24482, 13240, 2103
https://tests.stockfishchess.org/tests/view/5fd8d3740c5870924361ffad

Passed LTC:
LLR: 2.95 (-2.94,2.94) {0.25,1.25}
Total: 39384 W: 5334 L: 4990 D: 29060
Ptnml(0-2): 279, 3648, 11535, 3910, 320
https://tests.stockfishchess.org/tests/view/5fd971ab0c5870924361fff0

closes https://github.com/official-stockfish/Stockfish/pull/3266

Bench: 4488955

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index c507aa06a85f8a2bf4c84e4e038f3d0cdf72fc86..dd5d23b253dd074a0feef432367a899d9dc1e1b3 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -237,11 +237,11 @@ namespace {
 
   // PassedRank[Rank] contains a bonus according to the rank of a passed pawn
   constexpr Score PassedRank[RANK_NB] = {
 
   // PassedRank[Rank] contains a bonus according to the rank of a passed pawn
   constexpr Score PassedRank[RANK_NB] = {

-    S(0, 0), S(9, 28), S(15, 31), S(17, 39), S(64, 70), S(171, 177), S(277, 260)
+    S(0, 0), S(7, 27), S(16, 32), S(17, 40), S(64, 71), S(170, 174), S(278, 262)

   };
 
   constexpr Score RookOnClosedFile = S(10, 5);
   };
 
   constexpr Score RookOnClosedFile = S(10, 5);

-  constexpr Score RookOnOpenFile[] = { S(19, 7), S(48, 27) };
+  constexpr Score RookOnOpenFile[] = { S(19, 6), S(47, 26) };

 
   // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
   // which piece type attacks which one. Attacks on lesser pieces which are
 
   // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
   // which piece type attacks which one. Attacks on lesser pieces which are


@@ -788,9 +788,9 @@ namespace {
                 bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
 
                 if (!(pos.pieces(Them) & bb))
                 bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
 
                 if (!(pos.pieces(Them) & bb))

-                    unsafeSquares &= attackedBy[Them][ALL_PIECES];
+                    unsafeSquares &= attackedBy[Them][ALL_PIECES] | pos.pieces(Them);

 
 

-                // If there are no enemy attacks on passed pawn span, assign a big bonus.
+                // If there are no enemy pieces or attacks on passed pawn span, assign a big bonus.

                 // Otherwise assign a smaller bonus if the path to queen is not attacked
                 // and even smaller bonus if it is attacked but block square is not.
                 int k = !unsafeSquares                    ? 35 :
                 // Otherwise assign a smaller bonus if the path to queen is not attacked
                 // and even smaller bonus if it is attacked but block square is not.
                 int k = !unsafeSquares                    ? 35 :

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 16dbf27a5b105c3f8364d197b3913ac5f337ddfd..ed83fde72e5980d2a0cd8ff20f2df7f724b5675f 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -37,10 +37,10 @@ namespace {
   constexpr Score WeakUnopposed = S(13, 25);
 
   // Bonus for blocked pawns at 5th or 6th rank
   constexpr Score WeakUnopposed = S(13, 25);
 
   // Bonus for blocked pawns at 5th or 6th rank

-  constexpr Score BlockedPawn[2] = { S(-13, -4), S(-5, 2) };
+  constexpr Score BlockedPawn[2] = { S(-15, -3), S(-6, 3) };

 
   constexpr Score BlockedStorm[RANK_NB] = {
 
   constexpr Score BlockedStorm[RANK_NB] = {

-    S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)
+    S(0, 0), S(0, 0), S(75, 78), S(-8, 16), S(-6, 10), S(-6, 6), S(0, 2)

   };
 
   // Connected pawn bonus
   };
 
   // Connected pawn bonus