Apply good/bad history reduction also when inCheck

Main idea is that, in some cases, 'in check' situations are not so different from 'not in check' ones.
Trying to use piece count in order to select only a few 'in check' situations have failed LTC testing.
It could be interesting to apply one of those ideas in other parts of the search function.

passed STC:
https://tests.stockfishchess.org/tests/view/60f1b68dd1189bed71812d40
LLR: 2.93 (-2.94,2.94) <-2.50,0.50>
Total: 53472 W: 4078 L: 4008 D: 45386
Ptnml(0-2): 127, 3297, 19795, 3413, 104

passed LTC:
https://tests.stockfishchess.org/tests/view/60f291e6d1189bed71812de3
LLR: 2.92 (-2.94,2.94) <-2.50,0.50>
Total: 89712 W: 2651 L: 2632 D: 84429
Ptnml(0-2): 60, 2261, 40188, 2294, 53

closes https://github.com/official-stockfish/Stockfish/pull/3619

Bench: 5185789

diff --git a/AUTHORS b/AUTHORS
index 18471d4d0ec7d72d75f1d44b80789b0ff24e159e..4d72314f77b033978ae67d42c06002898c68c819 100644 (file)
--- a/AUTHORS
+++ b/AUTHORS
@@ -69,6 +69,7 @@ gamander
 Gary Heckman (gheckman)
 George Sobala (gsobala)
 gguliash
+Giacomo Lorenzetti (G-Lorenz)
 Gian-Carlo Pascutto (gcp)
 Gontran Lemaire (gonlem)
 Goodkov Vasiliy Aleksandrovich (goodkov)

diff --git a/src/search.cpp b/src/search.cpp
index 66402f0429a390d491aeaae86b26021e5f5de185..c41df1f0fdcb7005526a20ba2b349cfaa3c80542 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1172,8 +1172,7 @@ moves_loop: // When in check, search starts from here
                              - 4923;
 
               // Decrease/increase reduction for moves with a good/bad history (~30 Elo)
-              if (!ss->inCheck)
-                  r -= ss->statScore / 14721;
+              r -= ss->statScore / 14721;
           }
 
           // In general we want to cap the LMR depth search at newDepth. But if