Add capture history to the capture ordering

README.md

@@ -15,8 +15,8 @@ search, principal variation search, aspiration windows at the root, reverse futi
 null move pass, late move reductions and pruning off a margin under beta, quiet futility
 pruning and a late move count at the shallowest three depths, and the check and singular
 extensions. Captures are ordered by what a
-static exchange evaluation says the swap wins, with
-MVV-LVA breaking the ties between the ones it prices alike, and the quiet moves by the ones that
+static exchange evaluation says the swap wins, then by which captures have
+cut off before, with MVV-LVA breaking the ties, and the quiet moves by the ones that
 have cut off before. Evaluation is material, piece square tables, piece mobility, the
 pawns standing in front of each king, pawn structure, and the squares around each king the
 enemy pieces attack, and a tempo for the side to move, tapered between a middlegame and an

arche-core/src/bench.rs

@@ -616,8 +616,8 @@ mod tests {
             ],
             [
                 [182_505, 7_085, 22_788, 535, 0, 287, 0],
-                [10_070, 755, 2_598, 57, 28, 0, 0],
-                [12_991, 977, 3_364, 3, 0, 0, 47],
+                [10_197, 757, 2_633, 59, 29, 0, 0],
+                [13_152, 968, 3_392, 4, 0, 0, 41],
             ],
             "nodes, cutoffs, stores, tainted, tcuts, refused, skipped"
         );
@@ -833,22 +833,22 @@ mod tests {
         assert_eq!(
             counted,
             vec![
-                ("start", 810_901),
-                ("italian", 925_606),
-                ("ruy lopez", 568_063),
-                ("kiwipete", 1_717_616),
-                ("perft 4", 2_017_487),
-                ("promotions", 315_447),
-                ("middlegame", 519_737),
-                ("sharp middlegame", 683_004),
-                ("bratko kopec 1", 11_568),
+                ("start", 766_029),
+                ("italian", 685_915),
+                ("ruy lopez", 457_708),
+                ("kiwipete", 2_252_811),
+                ("perft 4", 1_346_541),
+                ("promotions", 1_800_032),
+                ("middlegame", 351_532),
+                ("sharp middlegame", 629_743),
+                ("bratko kopec 1", 11_454),
                 ("wac 4", 1_516),
-                ("rook and pawns", 314_171),
-                ("tarrasch", 186_731),
-                ("lucena", 442_470),
-                ("philidor", 190_861),
-                ("minor endgame", 185_295),
-                ("queen endgame", 360_712),
+                ("rook and pawns", 246_068),
+                ("tarrasch", 186_494),
+                ("lucena", 441_662),
+                ("philidor", 190_796),
+                ("minor endgame", 185_292),
+                ("queen endgame", 357_597),
                 ("king and pawn", 34_240),
                 ("trebuchet", 27_235),
             ]

arche-core/src/engine.rs

@@ -2178,7 +2178,7 @@ impl AlphaBeta {
                 }
             }
         }
-        // no memories here: they say nothing about captures or evasions
+        // no memories here: the main search alone reads them
         let Ordered { front, .. } =
             self.ordering
                 .order_split(&self.board, &mut moves, captures, pv_play, None, 0);