Avoid changing bestvalue

in the case the ttValue contains mate scores, do not return them as bestValue, since they are not proven. passed STC https://tests.stockfishchess.org/tests/view/665b1ea5586058766677cfa3 LLR: 2.93 (-2.94,2.94) <-1.75,0.25> Total: 58912 W: 15319 L: 15130 D: 28463 Ptnml(0-2): 141, 6562, 15854, 6765, 134 passed LTC: https://tests.stockfishchess.org/tests/view/665b2712586058766677cfc4 LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 141666 W: 35976 L: 35879 D: 69811 Ptnml(0-2): 61, 15513, 39584, 15618, 57 closes #5335 Bench: 1336115
official-stockfish · Jun 1, 2024 · b0870cf · b0870cf
1 parent 783dfc2
commit b0870cf
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/search.cpp b/src/search.cpp
@@ -1495,7 +1495,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
               to_corrected_static_eval(unadjustedStaticEval, *thisThread, pos);
 
             // ttValue can be used as a better position evaluation (~13 Elo)
-            if (ttValue != VALUE_NONE
+            if (std::abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY
                 && (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER)))
                 bestValue = ttValue;
         }