Maximize usage of transposition table in probcut

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index d365ba121c3e66a9e5bc2852113ecab62b36d4bd..7f8d451a6d47202ba0be9a814d0656ea90282bb4 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -38,6 +38,9 @@ namespace {
   constexpr Score WeakLever     = S( 0, 56);
   constexpr Score WeakUnopposed = S(13, 27);
 
+  // Bonus for blocked pawns at 5th or 6th rank
+  constexpr Score BlockedPawn[2] = { S(-11, -4), S(-3, 4) };
+
   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)
   };
@@ -145,7 +148,7 @@ namespace {
         // Score this pawn
         if (support | phalanx)
         {
-            int v =  Connected[r] * (4 + 2 * bool(phalanx) - 2 * bool(opposed) - bool(blocked)) / 2
+            int v =  Connected[r] * (2 + bool(phalanx) - bool(opposed))
                    + 21 * popcount(support);
 
             score += make_score(v, v * (r - 2) / 4);
@@ -169,6 +172,9 @@ namespace {
         if (!support)
             score -=  Doubled * doubled
                     + WeakLever * more_than_one(lever);
+
+        if (blocked && r > RANK_4)
+            score += BlockedPawn[r-4];
     }
 
     return score;