1 files changed, 9 insertions, 0 deletions
diff --git a/src/chess.h b/src/chess.h
index 9b6303d..3a78b2b 100755
--- a/src/chess.h
+++ b/src/chess.h
@@ -934,6 +934,10 @@ typedef struct _PLY_INFO
     FLAG fInCheck;
     FLAG fInQsearch;
     FLAG fPvNode;                             // this node's own window was wide
+    FLAG fMovesRescoredByIID;                 // sMoveStack[uPly].iValue holds
+                                               // real search scores from
+                                               // RescoreMovesViaSearch, not
+                                               // generate.c's ordering encoding
 
     MOVE mv;
     MOVE mvBest;
@@ -2284,6 +2288,11 @@ IsDraw(SEARCHER_THREAD_CONTEXT *ctx);
 //
 #define QPLIES_OF_NON_CAPTURE_CHECKS (2)
 #define FUTILITY_BASE_MARGIN         (50)
+// Measured: disabling this entirely (see lmr_testing/RESULTS.md) is a
+// clear net loss across ringers/confident_quick/hard_quick, so IID itself
+// is load-bearing. The "is the top move crappy" gate in search.c's DO_IID
+// block still misclassifies ordinary killer moves as crappy (see the fix
+// there) -- that's the next thing being tuned, not whether IID exists.
 #define DO_IID
 #define IID_R_FACTOR                 (TWO_PLY + HALF_PLY)