From 70b7404a63b74a57d4e1d0b9192b00837e9a1af8 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sat, 31 Oct 2009 10:51:04 +0100 Subject: [PATCH] Reorder evasions Always try ttMove as first. Then try good captures ordered by MVV/LVA, then non-captures if destination square is not under attack, ordered by history value, and at the end bad-captures and non-captures with a negative SEE. This last group is ordered by the SEE score. After 999 games at 1+0 Mod vs Orig +254 =546 -199 +19 ELO Signed-off-by: Marco Costalba --- src/movepick.cpp | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/src/movepick.cpp b/src/movepick.cpp index 0da6b61b..fdf4b8d1 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -197,8 +197,8 @@ void MovePicker::score_captures() { if (move_is_promotion(m)) cur->score = QueenValueMidgame; else - cur->score = int(pos.midgame_value_of_piece_on(move_to(m))) - -int(pos.type_of_piece_on(move_from(m))); + cur->score = pos.midgame_value_of_piece_on(move_to(m)) + - pos.type_of_piece_on(move_from(m)); } } @@ -229,19 +229,25 @@ void MovePicker::score_noncaptures() { } void MovePicker::score_evasions() { - + // Always try ttMove as first. Then try good captures ordered + // by MVV/LVA, then non-captures if destination square is not + // under attack, ordered by history value, and at the end + // bad-captures and non-captures with a negative SEE. This + // last group is ordered by the SEE score. Move m; + int seeScore; for (MoveStack* cur = moves; cur != lastMove; cur++) { m = cur->move; if (m == ttMoves[0].move) cur->score = 2 * HistoryMax; - else if (!pos.square_is_empty(move_to(m))) - { - int seeScore = pos.see(m); - cur->score = seeScore + (seeScore >= 0 ? HistoryMax : 0); - } else + else if ((seeScore = pos.see_sign(m)) < 0) + cur->score = seeScore; + else if (pos.move_is_capture(m)) + cur->score = pos.midgame_value_of_piece_on(move_to(m)) + - pos.type_of_piece_on(move_from(m)) + HistoryMax; + else cur->score = H.move_ordering_score(pos.piece_on(move_from(m)), move_to(m)); } } -- 2.39.2