Update reverse move stats

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 6d1a66e5f8688b24e6c5d9f96d7e8fd5c4b2c2c9..f8535a5f2e2851bfe1e387cc2ac0d735d422d1f4 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -64,7 +64,7 @@ namespace {
   // Razor and futility margins
   constexpr int RazorMargin = 661;
   Value futility_margin(Depth d, bool improving) {
   // Razor and futility margins
   constexpr int RazorMargin = 661;
   Value futility_margin(Depth d, bool improving) {

-    return Value((168 - 51 * improving) * d / ONE_PLY);
+    return Value(198 * (d / ONE_PLY - improving));

   }
 
   // Reductions lookup table, initialized at startup
   }
 
   // Reductions lookup table, initialized at startup


@@ -102,15 +102,16 @@ namespace {
     Move best = MOVE_NONE;
   };
 
     Move best = MOVE_NONE;
   };
 

-  // Breadcrumbs are used to mark nodes as being searched by a given thread.
+  // Breadcrumbs are used to mark nodes as being searched by a given thread

   struct Breadcrumb {
     std::atomic<Thread*> thread;
     std::atomic<Key> key;
   };
   std::array<Breadcrumb, 1024> breadcrumbs;
 
   struct Breadcrumb {
     std::atomic<Thread*> thread;
     std::atomic<Key> key;
   };
   std::array<Breadcrumb, 1024> breadcrumbs;
 

-  // ThreadHolding keeps track of which thread left breadcrumbs at the given node for potential reductions.
-  // A free node will be marked upon entering the moves loop, and unmarked upon leaving that loop, by the ctor/dtor of this struct.
+  // ThreadHolding structure keeps track of which thread left breadcrumbs at the given
+  // node for potential reductions. A free node will be marked upon entering the moves
+  // loop by the constructor, and unmarked upon leaving that loop by the destructor.

   struct ThreadHolding {
     explicit ThreadHolding(Thread* thisThread, Key posKey, int ply) {
        location = ply < 8 ? &breadcrumbs[posKey & (breadcrumbs.size() - 1)] : nullptr;
   struct ThreadHolding {
     explicit ThreadHolding(Thread* thisThread, Key posKey, int ply) {
        location = ply < 8 ? &breadcrumbs[posKey & (breadcrumbs.size() - 1)] : nullptr;


@@ -118,7 +119,7 @@ namespace {
        owning = false;
        if (location)
        {
        owning = false;
        if (location)
        {

-          // see if another already marked this location, if not, mark it ourselves.
+          // See if another already marked this location, if not, mark it ourselves

           Thread* tmp = (*location).thread.load(std::memory_order_relaxed);
           if (tmp == nullptr)
           {
           Thread* tmp = (*location).thread.load(std::memory_order_relaxed);
           if (tmp == nullptr)
           {


@@ -133,7 +134,7 @@ namespace {
     }
 
     ~ThreadHolding() {
     }
 
     ~ThreadHolding() {

-       if (owning) // free the marked location.
+       if (owning) // Free the marked location

            (*location).thread.store(nullptr, std::memory_order_relaxed);
     }
 
            (*location).thread.store(nullptr, std::memory_order_relaxed);
     }
 


@@ -341,7 +342,7 @@ void Thread::search() {
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
 

-  multiPV = Options["MultiPV"];
+  size_t multiPV = Options["MultiPV"];

 
   // Pick integer skill levels, but non-deterministically round up or down
   // such that the average integer skill corresponds to the input floating point one.
 
   // Pick integer skill levels, but non-deterministically round up or down
   // such that the average integer skill corresponds to the input floating point one.


@@ -471,7 +472,10 @@ void Thread::search() {
                   ++failedHighCnt;
               }
               else
                   ++failedHighCnt;
               }
               else

+              {
+                  ++rootMoves[pvIdx].bestMoveCount;

                   break;
                   break;

+              }

 
               delta += delta / 4 + 5;
 
 
               delta += delta / 4 + 5;
 


@@ -647,9 +651,9 @@ namespace {
     // statScore of the previous grandchild. This influences the reduction rules in
     // LMR which are based on the statScore of parent position.
     if (rootNode)
     // statScore of the previous grandchild. This influences the reduction rules in
     // LMR which are based on the statScore of parent position.
     if (rootNode)

-        (ss + 4)->statScore = 0;
+        (ss+4)->statScore = 0;

     else
     else

-        (ss + 2)->statScore = 0;
+        (ss+2)->statScore = 0;

 
     // Step 4. Transposition table lookup. We don't want the score of a partial
     // search to overwrite a previous full search TT value, so we use a different
 
     // Step 4. Transposition table lookup. We don't want the score of a partial
     // search to overwrite a previous full search TT value, so we use a different


@@ -680,7 +684,7 @@ namespace {
 
                 // Extra penalty for early quiet moves of the previous ply
                 if ((ss-1)->moveCount <= 2 && !pos.captured_piece())
 
                 // Extra penalty for early quiet moves of the previous ply
                 if ((ss-1)->moveCount <= 2 && !pos.captured_piece())

-                        update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
+                    update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));

             }
             // Penalty for a quiet ttMove that fails low
             else if (!pos.capture_or_promotion(ttMove))
             }
             // Penalty for a quiet ttMove that fails low
             else if (!pos.capture_or_promotion(ttMove))


@@ -798,7 +802,8 @@ namespace {
         && (ss-1)->currentMove != MOVE_NULL
         && (ss-1)->statScore < 22661
         &&  eval >= beta
         && (ss-1)->currentMove != MOVE_NULL
         && (ss-1)->statScore < 22661
         &&  eval >= beta

-        &&  ss->staticEval >= beta - 33 * depth / ONE_PLY + 299
+        &&  eval >= ss->staticEval
+        &&  ss->staticEval >= beta - 33 * depth / ONE_PLY + 299 - improving * 30

         && !excludedMove
         &&  pos.non_pawn_material(us)
         && (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor))
         && !excludedMove
         &&  pos.non_pawn_material(us)
         && (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor))


@@ -908,7 +913,7 @@ moves_loop: // When in check, search starts from here
     moveCountPruning = false;
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
 
     moveCountPruning = false;
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
 

-    // Mark this node as being searched.
+    // Mark this node as being searched

     ThreadHolding th(thisThread, posKey, ss->ply);
 
     // Step 12. Loop through all pseudo-legal moves until no moves remain
     ThreadHolding th(thisThread, posKey, ss->ply);
 
     // Step 12. Loop through all pseudo-legal moves until no moves remain


@@ -934,12 +939,6 @@ moves_loop: // When in check, search starts from here
           sync_cout << "info depth " << depth / ONE_PLY
                     << " currmove " << UCI::move(move, pos.is_chess960())
                     << " currmovenumber " << moveCount + thisThread->pvIdx << sync_endl;
           sync_cout << "info depth " << depth / ONE_PLY
                     << " currmove " << UCI::move(move, pos.is_chess960())
                     << " currmovenumber " << moveCount + thisThread->pvIdx << sync_endl;

-
-      // In MultiPV mode also skip moves which will be searched later as PV moves
-      if (rootNode && std::count(thisThread->rootMoves.begin() + thisThread->pvIdx + 1,
-                                 thisThread->rootMoves.begin() + thisThread->multiPV, move))
-          continue;
-

       if (PvNode)
           (ss+1)->pv = nullptr;
 
       if (PvNode)
           (ss+1)->pv = nullptr;
 


@@ -1076,10 +1075,12 @@ moves_loop: // When in check, search starts from here
       // Step 16. Reduced depth search (LMR). If the move fails high it will be
       // re-searched at full depth.
       if (    depth >= 3 * ONE_PLY
       // Step 16. Reduced depth search (LMR). If the move fails high it will be
       // re-searched at full depth.
       if (    depth >= 3 * ONE_PLY

-          &&  moveCount > 1 + 3 * rootNode
+          &&  moveCount > 1 + 2 * rootNode
+          && (!rootNode || thisThread->best_move_count(move) == 0)

           && (  !captureOrPromotion
               || moveCountPruning
           && (  !captureOrPromotion
               || moveCountPruning

-              || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha))
+              || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
+              || cutNode))

       {
           Depth r = reduction(improving, depth, moveCount);
 
       {
           Depth r = reduction(improving, depth, moveCount);
 


@@ -1112,7 +1113,7 @@ moves_loop: // When in check, search starts from here
               // castling moves, because they are coded as "king captures rook" and
               // hence break make_move(). (~5 Elo)
               else if (    type_of(move) == NORMAL
               // castling moves, because they are coded as "king captures rook" and
               // hence break make_move(). (~5 Elo)
               else if (    type_of(move) == NORMAL

-                       && !pos.see_ge(make_move(to_sq(move), from_sq(move))))
+                       && !pos.see_ge(reverse_move(move)))

                   r -= 2 * ONE_PLY;
 
               ss->statScore =  thisThread->mainHistory[us][from_to(move)]
                   r -= 2 * ONE_PLY;
 
               ss->statScore =  thisThread->mainHistory[us][from_to(move)]


@@ -1602,6 +1603,9 @@ moves_loop: // When in check, search starts from here
     thisThread->mainHistory[us][from_to(move)] << bonus;
     update_continuation_histories(ss, pos.moved_piece(move), to_sq(move), bonus);
 
     thisThread->mainHistory[us][from_to(move)] << bonus;
     update_continuation_histories(ss, pos.moved_piece(move), to_sq(move), bonus);
 

+    if (type_of(pos.moved_piece(move)) != PAWN)
+        thisThread->mainHistory[us][from_to(reverse_move(move))] << -bonus;
+

     if (is_ok((ss-1)->currentMove))
     {
         Square prevSq = to_sq((ss-1)->currentMove);
     if (is_ok((ss-1)->currentMove))
     {
         Square prevSq = to_sq((ss-1)->currentMove);