1.5.5

Alex2262 · Mar 31, 2023 · 2e0bf72 · 2e0bf72
1 parent ec3d402
commit 2e0bf72
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/changelog b/changelog
@@ -4619,3 +4619,17 @@ Score of Altair154 vs Altair153: 405 - 366 - 569  [0.515] 1340
 Elo difference: 10.1 +/- 14.1, LOS: 92.0 %, DrawRatio: 42.5 %
 SPRT: llr 0.735 (25.0%), lbound -2.94, ubound 2.94
 ```
+
+
+### 1.5.5
+Different quiet LMP scheme. No more depth constraint, however there is a new formula and it is also
+affected by the improving metric.
+
+```
+Score of Altair155 vs Altair154: 1771 - 1695 - 2394  [0.506] 5860
+...      Altair155 playing White: 1156 - 569 - 1205  [0.600] 2930
+...      Altair155 playing Black: 615 - 1126 - 1189  [0.413] 2930
+...      White vs Black: 2282 - 1184 - 2394  [0.594] 5860
+Elo difference: 4.5 +/- 6.8, LOS: 90.2 %, DrawRatio: 40.9 %
+SPRT: llr 0.823 (28.0%), lbound -2.94, ubound 2.94
+```
diff --git a/search.cpp b/search.cpp
@@ -474,7 +474,7 @@ SCORE_TYPE negamax(Engine& engine, Position& position, SCORE_TYPE alpha, SCORE_T
             if (depth <= 3 && legal_moves > depth * 8) break;
 
             // Quiet Late Move Pruning
-            if (quiet && depth <= 5 && legal_moves > depth * 6) break;
+            if (quiet && legal_moves > static_cast<int>((4 + 1.4 * depth * depth) * (1 - 0.25 * !improving))) break;
 
             // History Pruning
             if (depth <= 8 && move_history_score < (depth + improving) * -12000) continue;