Use a formula for chain membership bonus

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 4683a006ffe42c93f613a384f83df61b26418bcf..7e9b8d77216ae788475f4e7b351297d8b21dcdf8 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -143,17 +143,20 @@ void Search::init() {
 
       if (Reductions[0][0][hd][mc] > 2 * ONE_PLY)
           Reductions[0][0][hd][mc] += ONE_PLY;
+
+      else if (Reductions[0][0][hd][mc] > 1 * ONE_PLY)
+          Reductions[0][0][hd][mc] += ONE_PLY / 2;
   }
 
   // Init futility margins array
   for (d = 1; d < 16; ++d) for (mc = 0; mc < 64; ++mc)
-      FutilityMargins[d][mc] = Value(112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45);
+      FutilityMargins[d][mc] = Value(112 * int(2.9 * log(double(d))) - 8 * mc + 45);
 
   // Init futility move count array
   for (d = 0; d < 32; ++d)
   {
-      FutilityMoveCounts[0][d] = int(3 + 0.3 * pow(double(d       ), 1.8)) * 3/4 + (2 < d && d < 5);
-      FutilityMoveCounts[1][d] = int(3 + 0.3 * pow(double(d + 0.98), 1.8));
+      FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d +  0.0, 1.8));
+      FutilityMoveCounts[1][d] = int(3.0 +   0.3 * pow(d + 0.98, 1.8));
   }
 }