Simplify ttPv reduction formula

This patch is based on the fact that the ttPv reduction has proven non-linear scaling (as documented in the code, along with testing guidelines); however, the original patch had (erroneously) not been tested at VLTC or longer.
official-pikafish · Jul 7, 2024 · eef540b · eef540b
1 parent b2b429c
commit eef540b
Showing 1 changed file with 1 addition and 2 deletions.
diff --git a/src/search.cpp b/src/search.cpp
@@ -1042,8 +1042,7 @@ Value Search::Worker::search(
 
         // Decrease reduction if position is or has been on the PV (~7 Elo)
         if (ss->ttPv)
-            r -= 1 + (ttData.value > alpha) + (ttData.depth >= depth)
-               - (PvNode && ttData.value < alpha && ttData.depth >= depth);
+            r -= 1 + (ttData.value > alpha) + (ttData.depth >= depth);
 
         // Decrease reduction for PvNodes (~0 Elo on STC, ~2 Elo on LTC)
         if (PvNode)