Scale down eval for drawish rook endgames.

[stockfish] / src / movepick.cpp

diff --git a/src/movepick.cpp b/src/movepick.cpp
index b1e10587cf4a1496d9cb68ed6fc8e10b1e4190c3..5775f810600286959e24541a76337caa05d7a81c 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -57,7 +57,7 @@ namespace {
 
 /// MovePicker constructor for the main search
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const LowPlyHistory* lp,
-                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers, int pl)
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl)
            : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch),
              ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) {
 
@@ -110,7 +110,7 @@ void MovePicker::score() {
                    + 2 * (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
                    + 2 * (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)]
                    +     (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
-                   + (ply < MAX_LPH ?  4 * (*lowPlyHistory)[ply][from_to(m)] : 0);
+                   + (ply < MAX_LPH ? std::min(4, depth / 3) * (*lowPlyHistory)[ply][from_to(m)] : 0);
 
       else // Type == EVASIONS
       {
@@ -169,7 +169,7 @@ top:
 
   case GOOD_CAPTURE:
       if (select<Best>([&](){
-                       return pos.see_ge(*cur, Value(-55 * cur->value / 1024)) ?
+                       return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ?
                               // Move losing capture to endBadCaptures to be tried later
                               true : (*endBadCaptures++ = *cur, false); }))
           return *(cur - 1);