Introduce bad outpost penalty

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 6f2dd69ba33d7a5986fe99be7d70493d29023c76..ca6ea5c44fd6da373d4e1cf9bf10deca66d2771f 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -134,6 +134,7 @@ namespace {
   };
 
   // Assorted bonuses and penalties
+  constexpr Score BadOutpost          = S( -7, 36);
   constexpr Score BishopOnKingRing    = S( 24,  0);
   constexpr Score BishopPawns         = S(  3,  7);
   constexpr Score BishopXRayPawns     = S(  4,  5);
@@ -310,7 +311,13 @@ namespace {
         {
             // Bonus if piece is on an outpost square or can reach one
             bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
-            if (bb & s)
+            if (   Pt == KNIGHT
+                && bb & s & ~CenterFiles
+                && !(b & pos.pieces(Them) & ~pos.pieces(PAWN))
+                && !conditional_more_than_two(
+                      pos.pieces(Them) & ~pos.pieces(PAWN) & (s & QueenSide ? QueenSide : KingSide)))
+                score += BadOutpost;
+            else if (bb & s)
                 score += Outpost[Pt == BISHOP];
             else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us))
                 score += ReachableOutpost;