diff --git a/src/Ceres.MCTS/Evaluators/LeafEvaluatorTransposition.cs b/src/Ceres.MCTS/Evaluators/LeafEvaluatorTransposition.cs
index 294f6490..3b05e9af 100644
--- a/src/Ceres.MCTS/Evaluators/LeafEvaluatorTransposition.cs
+++ b/src/Ceres.MCTS/Evaluators/LeafEvaluatorTransposition.cs
@@ -37,6 +37,13 @@ namespace Ceres.MCTS.Evaluators
   /// </summary>
   public sealed partial class LeafEvaluatorTransposition : LeafEvaluatorBase
   {
+    // If TestMetric and TestCounter should track the number of
+    // virtual visits whih obviate node allocation (TestCounter1) 
+    // and also the number of nodes which subsequently had to be materialized (TestMetric)
+    // and were therefore not ultimately actual memory savings.
+    // Disabled by default due to performance impact (especially due to false sharing).
+    internal const bool TRACK_VIRTUAL_VISITS = false;
+
     // TODO: Transposition counts temporarily disabled for performance reasons (false sharing)
     static ulong NumHits = 0;
     static ulong NumMisses = 0;
diff --git a/src/Ceres.MCTS/MCTSNodes/Struct/MCTSNodeStructClone.cs b/src/Ceres.MCTS/MCTSNodes/Struct/MCTSNodeStructClone.cs
index f53ac823..85e6ba4d 100644
--- a/src/Ceres.MCTS/MCTSNodes/Struct/MCTSNodeStructClone.cs
+++ b/src/Ceres.MCTS/MCTSNodes/Struct/MCTSNodeStructClone.cs
@@ -161,7 +161,10 @@ public static MCTSNodeStructIndex TryCloneChild(MCTSTree tree,
       // TODO: avoid ChildAtIndex to avoid dictionary lookup?
       targetChildRef.CopyUnexpandedChildrenFromOtherNode(tree, new MCTSNodeStructIndex(sourceChildRef.Index.Index));
 
-      MCTSEventSource.TestMetric1++;
+      if (LeafEvaluatorTransposition.TRACK_VIRTUAL_VISITS)
+      {
+        MCTSEventSource.TestMetric1++;
+      }
 
       Debug.Assert(!double.IsNaN(sourceParentRef.W));
       Debug.Assert(!double.IsNaN(sourceChildRef.W));
diff --git a/src/Ceres.MCTS/Search/MCTSApply.cs b/src/Ceres.MCTS/Search/MCTSApply.cs
index a641c199..ba156751 100644
--- a/src/Ceres.MCTS/Search/MCTSApply.cs
+++ b/src/Ceres.MCTS/Search/MCTSApply.cs
@@ -237,7 +237,10 @@ void ApplyResult(Span<MCTSNodeStruct> nodes, int selectorID, MCTSNode node, Leaf
           numToApply = Math.Min(nodeRef.NumVisitsPendingTranspositionRootExtraction, numToApply);
 
           // Increment count of number of "extra" (beyond 1) values used without tree replication.
-          if (nodeRef.NumVisitsPendingTranspositionRootExtraction > 1) MCTSEventSource.TestCounter1++;
+          if (LeafEvaluatorTransposition.TRACK_VIRTUAL_VISITS && nodeRef.NumVisitsPendingTranspositionRootExtraction > 1)
+          {
+            MCTSEventSource.TestCounter1++;
+          }
 
           // Switch to propagate this "pseudo V" for this node and all nodes above
           vToApply = node.PendingTranspositionV;