Re-introduce "keep pawns on both flanks"

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 0021c088c0aa0ef88f6076aa43df9554faa3fa16..4a4ae2ad982b430d941dbcaca85af66a0eb0bf12 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -758,12 +758,16 @@ namespace {
     int outflanking =  distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
                      - distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
 
+    bool pawnsOnBothFlanks =   (pos.pieces(PAWN) & QueenSide)          
+                            && (pos.pieces(PAWN) & KingSide);
+
     // Compute the initiative bonus for the attacking side
     int complexity =   8 * pe->pawn_asymmetry()
                     + 12 * pos.count<PAWN>()
                     + 12 * outflanking
+                    + 16 * pawnsOnBothFlanks
                     + 48 * !pos.non_pawn_material()
-                    -110 ;
+                    -118 ;
 
     // Now apply the bonus: note that we find the attacking side by extracting
     // the sign of the endgame value, and that we carefully cap the bonus so