Revert "Enhanced verify search (official-stockfish#1338)"

This reverts commit b53239d.
NiTeFiSe · Mar 31, 2018 · 63ba8d4 · 63ba8d4
1 parent 2198cd0
commit 63ba8d4
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Showing 3 changed files with 2 additions and 14 deletions.
diff --git a/src/search.cpp b/src/search.cpp
@@ -681,8 +681,7 @@ namespace {
     // Step 8. Null move search with verification search (is omitted in PV nodes)
     if (   !PvNode
         &&  eval >= beta
-        &&  ss->staticEval >= beta - 36 * depth / ONE_PLY + 225
-		&& (ss->ply >= thisThread->nmp_ply || ss->ply % 2 == thisThread->pair))
+        &&  ss->staticEval >= beta - 36 * depth / ONE_PLY + 225)
     {
 
         assert(eval - beta >= 0);
@@ -708,17 +707,8 @@ namespace {
                 return nullValue;
 
             // Do verification search at high depths
-            R += ONE_PLY;
-            // disable null move pruning for side to move for the first part of the remaining search tree
-            int nmp_ply = thisThread->nmp_ply;
-            int pair = thisThread->pair;
-            thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4;
-            thisThread->pair = (ss->ply % 2) == 0;
-
             Value v = depth-R < ONE_PLY ? qsearch<NonPV, false>(pos, ss, beta-1, beta)
                                         :  search<NonPV>(pos, ss, beta-1, beta, depth-R, false, true);
-            thisThread->pair = pair;
-            thisThread->nmp_ply = nmp_ply;
 
             if (v >= beta)
                 return nullValue;

diff --git a/src/thread.cpp b/src/thread.cpp
@@ -187,8 +187,6 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
       th->rootDepth = th->completedDepth = DEPTH_ZERO;
       th->rootMoves = rootMoves;
       th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
-      th->nmp_ply = 0;
-      th->pair = -1;
   }
 
   setupStates->back() = tmp;

diff --git a/src/thread.h b/src/thread.h
@@ -61,7 +61,7 @@ class Thread {
   Material::Table materialTable;
   Endgames endgames;
   size_t PVIdx;
-  int selDepth, nmp_ply, pair;
+  int selDepth;
   std::atomic<uint64_t> nodes, tbHits;
 
   Position rootPos;