Two ideas:

1. Nullmove R=3 + depth/6 along with some ShouldWeDoNullmoveSearch
tweaking and calibrating.

2. Probe EGTB everywhere in the search as long as the table/position
is resident in memory.

1 files changed, 15 insertions, 40 deletions

diff --git a/src/root.c b/src/root.c
index a8a61bf..86d8b76 100644
--- a/src/root.c
+++ b/src/root.c
@@ -501,46 +501,6 @@ Return value:
         Trace("Never used endgame pruning heuristic.\n");
     }
 #endif
-#ifdef TEST_NULL
-    n = (double)(ctx->sCounters.tree.u64AvoidNullSuccess);
-    d = n + (double)(ctx->sCounters.tree.u64AvoidNullFailures);
-    if (d != 0.0)
-    {
-        Trace("Avoid null move heuristic rate was %5.3f percent.\n"
-              "Avoid null move heuristic was "
-              "%"COMPILER_LONGLONG_UNSIGNED_FORMAT " / "
-              "%"COMPILER_LONGLONG_UNSIGNED_FORMAT ".\n",
-              ((n / d) * 100.0),
-              ctx->sCounters.tree.u64AvoidNullSuccess,
-              (ctx->sCounters.tree.u64AvoidNullSuccess +
-               ctx->sCounters.tree.u64AvoidNullFailures));
-    }
-    else
-    {
-        Trace("Never used the avoid null move heuristic.\n");
-    }
-    n = (double)(ctx->sCounters.tree.u64QuickNullSuccess);
-    n += (double)(ctx->sCounters.tree.u64QuickNullDeferredSuccess);
-    d = n + (double)(ctx->sCounters.tree.u64QuickNullFailures);
-    if (d != 0.0)
-    {
-        Trace("Quick null move heuristic rate was %5.3f percent.\n"
-              "Quick null move heuristic rate was "
-              "%"COMPILER_LONGLONG_UNSIGNED_FORMAT " ("
-              "%"COMPILER_LONGLONG_UNSIGNED_FORMAT ") / "
-              "%"COMPILER_LONGLONG_UNSIGNED_FORMAT ".\n",
-              ((n / d) * 100.0),
-              ctx->sCounters.tree.u64QuickNullSuccess,
-              ctx->sCounters.tree.u64QuickNullDeferredSuccess,
-              (ctx->sCounters.tree.u64QuickNullSuccess +
-               ctx->sCounters.tree.u64QuickNullDeferredSuccess +
-               ctx->sCounters.tree.u64QuickNullFailures));
-    }
-    else
-    {
-        Trace("Never used the quick null move heuristic.\n");
-    }
-#endif
     n = (double)ctx->sCounters.tree.u64BetaCutoffsOnFirstMove;
     d = (double)ctx->sCounters.tree.u64BetaCutoffs + 1;
     Trace("First move beta cutoff rate was %5.3f percent.\n",
@@ -1547,6 +1507,21 @@ Return value:
         g_Options.u64CMEvidenceTries[u] = ctx->sCounters.tree.u64CMEvidenceTries[u];
         g_Options.u64CMEvidenceFH[u] = ctx->sCounters.tree.u64CMEvidenceFH[u];
     }
+#ifdef TEST_NULL
+    for (u = 0; u < NC_TOTAL_BUCKETS; u++)
+    {
+        g_Options.u64NCAttempts[u] = ctx->sCounters.tree.u64NCAttempts[u];
+        g_Options.u64NCNullFH[u] = ctx->sCounters.tree.u64NCNullFH[u];
+        g_Options.u64NCRealFH[u] = ctx->sCounters.tree.u64NCRealFH[u];
+        g_Options.u64NCBothFH[u] = ctx->sCounters.tree.u64NCBothFH[u];
+        g_Options.u64NCNullProbeNodeSum[u] =
+            ctx->sCounters.tree.u64NCNullProbeNodeSum[u];
+        g_Options.u64NCFirstMoveNodeSum[u] =
+            ctx->sCounters.tree.u64NCFirstMoveNodeSum[u];
+        g_Options.u64NCRealLoopNodeSum[u] =
+            ctx->sCounters.tree.u64NCRealLoopNodeSum[u];
+    }
+#endif
     g_MoveTimer.dEndTime = SystemTimeStamp();
 
     //