X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=4b6b497a5b49b504031519b5fcb8137d6a76d1b9;hb=f436bf77ad2eb42228747d9aa58eeb7403e23d49;hp=c998f20d156bb260ac6aaced49b1835bcfa84ead;hpb=1591e5ac3b24f068f965471f17d7aae33ceaab9f;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index c998f20d..4b6b497a 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -309,9 +309,8 @@ void Thread::search() {
 
   complexityAverage.set(155, 1);
 
-  trend         = SCORE_ZERO;
-  optimism[ us] = Value(37);
-  optimism[~us] = -optimism[us];
+  trend = SCORE_ZERO;
+  optimism[us] = optimism[~us] = VALUE_ZERO;
 
   int searchAgainCounter = 0;
 
@@ -358,11 +357,11 @@ void Thread::search() {
               beta  = std::min(prev + delta, VALUE_INFINITE);
 
               // Adjust trend and optimism based on root move's previousScore
-              int tr = sigmoid(prev, 3, 10, 89, 116, 1);
+              int tr = 116 * prev / (std::abs(prev) + 89);
               trend = (us == WHITE ?  make_score(tr, tr / 2)
                                    : -make_score(tr, tr / 2));
 
-              int opt = sigmoid(prev, 7, 20, 169, 19350, 164);
+              int opt = 118 * prev / (std::abs(prev) + 169);
               optimism[ us] = Value(opt);
               optimism[~us] = -optimism[us];
           }
@@ -790,7 +789,7 @@ namespace {
         &&  depth < 8
         &&  eval - futility_margin(depth, improving) - (ss-1)->statScore / 303 >= beta
         &&  eval >= beta
-        &&  eval < 28031) // larger than VALUE_KNOWN_WIN, but smaller than TB wins.
+        &&  eval < 28031) // larger than VALUE_KNOWN_WIN, but smaller than TB wins
         return eval;
 
     // Step 9. Null move search with verification search (~22 Elo)
@@ -1164,7 +1163,12 @@ moves_loop: // When in check, search starts here
           if (singularQuietLMR)
               r--;
 
-          // Increase reduction if next ply has a lot of fail high else reset count to 0
+          // Dicrease reduction if we move a threatened piece (~1 Elo)
+          if (   depth > 9
+              && (mp.threatenedPieces & from_sq(move)))
+              r--;
+
+          // Increase reduction if next ply has a lot of fail high
           if ((ss+1)->cutoffCnt > 3 && !PvNode)
               r++;
 
@@ -1861,12 +1865,9 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) {
           ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
 
       ss << " nodes "    << nodesSearched
-         << " nps "      << nodesSearched * 1000 / elapsed;
-
-      if (elapsed > 1000) // Earlier makes little sense
-          ss << " hashfull " << TT.hashfull();
-
-      ss << " tbhits "   << tbHits
+         << " nps "      << nodesSearched * 1000 / elapsed
+         << " hashfull " << TT.hashfull()
+         << " tbhits "   << tbHits
          << " time "     << elapsed
          << " pv";