Tweak stat bonus

locutus2 · snicolet · commit c4c2e08f0d71 · 2018-07-25T18:02:07.000+02:00
Increase stat bonus by 1/32 and adjust the divisor of main and capture history tables to 10692. STC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 28437 W: 6444 L: 6166 D: 15827 http://tests.stockfishchess.org/tests/view/5b579b4d0ebc5902bdb87139 LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 111204 W: 19160 L: 18644 D: 73400 http://tests.stockfishchess.org/tests/view/5b57a7c60ebc5902bdb872d3 Closes #1698 Bench: 4778882
diff --git a/src/movepick.h b/src/movepick.h
@@ -85,14 +85,14 @@ enum StatsParams { NOT_USED = 0 };
 /// unsuccessful during the current search, and is used for reduction and move
 /// ordering decisions. It uses 2 tables (one for each color) indexed by
 /// the move's from and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
-typedef Stats<int16_t, 10368, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
+typedef Stats<int16_t, 10692, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
 
 /// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
 /// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
 typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
 
 /// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
-typedef Stats<int16_t, 10368, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
+typedef Stats<int16_t, 10692, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
 
 /// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
 typedef Stats<int16_t, 29952, PIECE_NB, SQUARE_NB> PieceToHistory;
diff --git a/src/search.cpp b/src/search.cpp
@@ -82,7 +82,7 @@ namespace {
   // History and stats update bonus, based on depth
   int stat_bonus(Depth depth) {
     int d = depth / ONE_PLY;
-    return d > 17 ? 0 : 32 * d * d + 64 * d - 64;
+    return d > 17 ? 0 : 33 * d * d + 66 * d - 66;
   }
 
   // Skill structure is used to implement strength limit

Original file line number	Diff line number	Diff line change
`@@ -82,7 +82,7 @@ namespace {`
`82`	`82`	`// History and stats update bonus, based on depth`
`83`	`83`	`int stat_bonus(Depth depth) {`
`84`	`84`	`int d = depth / ONE_PLY;`
`85`		`- return d > 17 ? 0 : 32 * d * d + 64 * d - 64;`
	`85`	`+ return d > 17 ? 0 : 33 * d * d + 66 * d - 66;`
`86`	`86`	`}`
`87`	`87`
`88`	`88`	`// Skill structure is used to implement strength limit`