Simplify LMR multiThread condition

BM123499 · snicolet · commit 1163d972a9a1 · 2021-10-24T22:08:28.000+02:00
STC (8 threads): LLR: 2.95 (-2.94,2.94) <-2.50,0.50> Total: 110584 W: 27818 L: 27807 D: 54959 Ptnml(0-2): 156, 12089, 30791, 12100, 156 https://tests.stockfishchess.org/tests/view/6172ef436ce927be325583a9 LTC (8 threads): LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 23632 W: 6025 L: 5903 D: 11704 Ptnml(0-2): 5, 2292, 7100, 2414, 5 https://tests.stockfishchess.org/tests/view/6173cf096ce927be32558412 closes #3757 No functional change (in the single-threaded case) Bench: 6689428
diff --git a/src/search.cpp b/src/search.cpp
@@ -1159,10 +1159,9 @@ namespace {
       // cases where we extend a son if it has good chances to be "interesting".
       if (    depth >= 3
           &&  moveCount > 1 + 2 * rootNode
-          && (  !captureOrPromotion
-              || (cutNode && (ss-1)->moveCount > 1)
-              || !ss->ttPv)
-          && (!PvNode || ss->ply > 1 || thisThread->id() % 4 != 3))
+          && (   !ss->ttPv
+              || !captureOrPromotion
+              || (cutNode && (ss-1)->moveCount > 1)))
       {
           Depth r = reduction(improving, depth, moveCount, rangeReduction > 2);
 
