Avoid engames with blocked center and lots of pawns

snicolet · Mar 12, 2018 · 0ddd1a7 · 0ddd1a7
1 parent 6e9337b
commit 0ddd1a7
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
@@ -172,6 +172,7 @@ namespace {
   const Score LongRangedBishop  = S( 22,  0);
   const Score MinorBehindPawn   = S( 16,  0);
   const Score PawnlessFlank     = S( 20, 80);
+  const Score PawnMobility      = S(  0,  8);
   const Score RookOnPawn        = S(  8, 24);
   const Score SliderOnQueen     = S( 42, 21);
   const Score ThreatByPawnPush  = S( 47, 26);
@@ -577,6 +578,10 @@ namespace {
     b &= ~attackedBy[Them][PAWN]
         & (attackedBy[Us][ALL_PIECES] | ~attackedBy[Them][ALL_PIECES]);
 
+    // Pawn mobility, to keep fluidity of position
+    if (pos.count<PAWN>() >= 10)
+        score += PawnMobility * popcount(b & CenterFiles);
+
     // Bonus for safe pawn threats on the next move
     b =   pawn_attacks_bb<Us>(b)
        &  pos.pieces(Them)