Revert dynamic LMR

It doesn't seem to work against Toga. After more then 400 games
we are at -13 ELO while, without it we are at + 5 ELO after 1000
games.

So revert for now to keep code simple.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/search.cpp b/src/search.cpp
index 806a9be135e40237c1865987258b008f48efe19a..f18f2f2f65035a9c3740d92b551707e4030e8bfd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -121,9 +121,6 @@ namespace {
   // Depth limit for selective search:
   Depth SelectiveDepth = 7*OnePly;
 
-  // Use dynamic LMR?
-  const bool UseDynamicLMR = false;
-
   // Use internal iterative deepening?
   const bool UseIIDAtPVNodes = true;
   const bool UseIIDAtNonPVNodes = false;
@@ -1335,13 +1332,8 @@ namespace {
           && !move_is_castle(move)
           && !move_is_killer(move, ss[ply]))
       {
-          // LMR dynamic reduction
-          Depth R =    UseDynamicLMR
-                    && moveCount >= 2 * LMRNonPVMoves
-                    && depth > 7*OnePly ? 2*OnePly : OnePly;
-
-          ss[ply].reduction = R;
-          value = -search(pos, ss, -(beta-1), newDepth-R, ply+1, true, threadID);
+          ss[ply].reduction = OnePly;
+          value = -search(pos, ss, -(beta-1), newDepth-OnePly, ply+1, true, threadID);
       }
       else
         value = beta; // Just to trigger next condition