Multiple lazy stages.

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 48db2b3be4334d719d2175bf65ae8e5337fc8207..dbb725d4dbf558639b2ce9daf80532d992681e74 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -74,7 +74,8 @@ using namespace Trace;
 namespace {
 
   // Threshold for lazy and space evaluation
-  constexpr Value LazyThreshold  = Value(1400);
+  constexpr Value LazyThreshold1  = Value(1400);
+  constexpr Value LazyThreshold2  = Value(1300);
   constexpr Value SpaceThreshold = Value(12222);
 
   // KingAttackWeights[PieceType] contains king attack weights by piece type
@@ -134,6 +135,7 @@ namespace {
   };
 
   // Assorted bonuses and penalties
+  constexpr Score BadOutpost          = S( -7, 36);
   constexpr Score BishopOnKingRing    = S( 24,  0);
   constexpr Score BishopPawns         = S(  3,  7);
   constexpr Score BishopXRayPawns     = S(  4,  5);
@@ -310,7 +312,13 @@ namespace {
         {
             // Bonus if piece is on an outpost square or can reach one
             bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
-            if (bb & s)
+            if (   Pt == KNIGHT
+                && bb & s & ~CenterFiles
+                && !(b & pos.pieces(Them) & ~pos.pieces(PAWN))
+                && !conditional_more_than_two(
+                      pos.pieces(Them) & ~pos.pieces(PAWN) & (s & QueenSide ? QueenSide : KingSide)))
+                score += BadOutpost;
+            else if (bb & s)
                 score += Outpost[Pt == BISHOP];
             else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us))
                 score += ReachableOutpost;
@@ -719,9 +727,9 @@ namespace {
   }
 
 
-  // Evaluation::winnable() adjusts the mg and eg score components based on the
-  // known attacking/defending status of the players. A single value is derived
-  // by interpolation from the mg and eg values and returned.
+  // Evaluation::winnable() adjusts the midgame and endgame score components, based on
+  // the known attacking/defending status of the players. The final value is derived
+  // by interpolation from the midgame and endgame values.
 
   template<Tracing T>
   Value Evaluation<T>::winnable(Score score) const {
@@ -764,7 +772,7 @@ namespace {
     Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
     int sf = me->scale_factor(pos, strongSide);
 
-    // If scale is not already specific, scale down the endgame via general heuristics
+    // If scale factor is not already specific, scale down via general heuristics
     if (sf == SCALE_FACTOR_NORMAL)
     {
         if (pos.opposite_bishops())
@@ -777,7 +785,6 @@ namespace {
         }
         else if (  pos.non_pawn_material(WHITE) == RookValueMg
                 && pos.non_pawn_material(BLACK) == RookValueMg
-                && !pe->passed_pawns(strongSide)
                 && pos.count<PAWN>(strongSide) - pos.count<PAWN>(~strongSide) <= 1
                 && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN))
                 && (attacks_bb<KING>(pos.square<KING>(~strongSide)) & pos.pieces(~strongSide, PAWN)))
@@ -831,9 +838,12 @@ namespace {
     score += pe->pawn_score(WHITE) - pe->pawn_score(BLACK);
 
     // Early exit if score is high
-    Value v = (mg_value(score) + eg_value(score)) / 2;
-    if (abs(v) > LazyThreshold + pos.non_pawn_material() / 64)
-       return pos.side_to_move() == WHITE ? v : -v;
+    auto lazy_skip = [&](Value lazyThreshold) {
+        return abs(mg_value(score) + eg_value(score)) / 2 > lazyThreshold + pos.non_pawn_material() / 64;
+    };
+
+    if (lazy_skip(LazyThreshold1))
+        goto make_v;
 
     // Main evaluation begins here
     initialize<WHITE>();
@@ -850,12 +860,17 @@ namespace {
 
     // More complex interactions that require fully populated attack bitboards
     score +=  king<   WHITE>() - king<   BLACK>()
-            + threats<WHITE>() - threats<BLACK>()
-            + passed< WHITE>() - passed< BLACK>()
+            + passed< WHITE>() - passed< BLACK>();
+
+    if (lazy_skip(LazyThreshold2))
+        goto make_v;
+
+    score +=  threats<WHITE>() - threats<BLACK>()
             + space<  WHITE>() - space<  BLACK>();
 
+make_v:
     // Derive single value from mg and eg parts of score
-    v = winnable(score);
+    Value v = winnable(score);
 
     // In case of tracing add all remaining individual evaluation terms
     if (T)