Simplify lowply-history scoring logic

STC:
https://tests.stockfishchess.org/tests/view/60eee559d1189bed71812b16
LLR: 2.97 (-2.94,2.94) <-2.50,0.50>
Total: 33976 W: 2523 L: 2431 D: 29022
Ptnml(0-2): 66, 2030, 12730, 2070, 92

LTC:
https://tests.stockfishchess.org/tests/view/60eefa12d1189bed71812b24
LLR: 2.93 (-2.94,2.94) <-2.50,0.50>
Total: 107240 W: 3053 L: 3046 D: 101141
Ptnml(0-2): 56, 2668, 48154, 2697, 45

closes https://github.com/official-stockfish/Stockfish/pull/3616

bench: 5199177

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 4ff4cff44b448f518a534a776b1321eef83387ba..20640fe2b02d8bd65773c8bdf135a9f56d51922c 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -111,7 +111,7 @@ void MovePicker::score() {
                    +     (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
                    +     (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)]
                    +     (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
-                   + (ply < MAX_LPH ? std::min(4, depth / 3) * (*lowPlyHistory)[ply][from_to(m)] : 0);
+                   + (ply < MAX_LPH ? 6 * (*lowPlyHistory)[ply][from_to(m)] : 0);
 
       else // Type == EVASIONS
       {