Let to toggle dynamic LMR

It is now disabled by default due to bad results
against a pool of engines...more testing is needed tough.

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

diff --git a/src/search.cpp b/src/search.cpp
index c4446fc5d95bd4a6271fca322eb5b75ec8610d91..f52351920a369831119c2fecc65d483e626dfd9a 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -121,6 +121,9 @@ namespace {
   // Depth limit for selective search:
   Depth SelectiveDepth = 7*OnePly;
 
   // 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;
   // Use internal iterative deepening?
   const bool UseIIDAtPVNodes = true;
   const bool UseIIDAtNonPVNodes = false;


@@ -1333,7 +1336,9 @@ namespace {
           && !move_is_killer(move, ss[ply]))
       {
           // LMR dynamic reduction
           && !move_is_killer(move, ss[ply]))
       {
           // LMR dynamic reduction

-          Depth R = (moveCount >= 2 * LMRNonPVMoves && depth > 7*OnePly ? 2*OnePly : OnePly);
+          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 = R;
           value = -search(pos, ss, -(beta-1), newDepth-R, ply+1, true, threadID);