@@ -155,7 +155,8 @@ shippable, so an oversized hub is addressable debt rather than accepted state.
   statement texts close it down to a stated threshold: two identical normalized statements from
   one deleted source is the move signal, one is tolerated as coincidence (short constants repeat
   across the repo), and a transplant rewritten statement-by-statement stays outside a textual
-  probe — what remains heuristic-free is the LIST of deleted sources (an `-M`-less diff), not the
+  probe — what remains heuristic-free is the LIST of deleted sources (git's own delete listing,
+  needing no similarity pairing to have been attempted), not the
   content match.
 - **Weight alone (#2469 candidate 1):** refuted by the planted drop test — a swap can keep the
   statement total flat while quietly making the closure evaluate different modules.
 
@@ -80,10 +80,11 @@ export function closureGrowthEvidence(params: {
   renamedBaseToHead?: ReadonlyMap<string, string>;
   /**
    * Weight-bearing statement texts of each merge-base production source DELETED since the
-   * merge-base (`deletedSourcesSince`, which deliberately skips `-M`, mapped through
-   * `statementTextsOf`). Git's rename detection is a similarity heuristic and a rewritten move
-   * evades it, showing up as delete + brand-new path; content is not a heuristic, so an added
-   * module carrying a deleted source's code is a move of pre-existing code, not a new file.
+   * merge-base (`deletedSourcesSince`, which lists only the deletions git's DEFAULT rename
+   * pairing did not absorb, mapped through `statementTextsOf`). Git's rename detection is a
+   * similarity heuristic and a rewritten move evades it, showing up as delete + brand-new path;
+   * content is not a heuristic, so an added module carrying a deleted source's code is a move of
+   * pre-existing code, not a new file.
    */
   deletedSourceTexts?: readonly (readonly string[])[];
 }): ClosureGrowthEvidence {
 
@@ -55,10 +55,14 @@ export function renamedSince(repoRoot: string, base: string): ReadonlyMap<string
 }
 
 /**
- * Production source paths tracked at `base` but gone from the working tree, WITHOUT `-M`, so a
- * rename the similarity detector would pair stays visible here too. `renamedSince` answers by
- * detection and misses a moved-and-rewritten module; the split tolerance reads these paths'
- * content directly so such a move stays non-novel (#3298 review).
+ * Production source paths tracked at `base` but gone from the working tree. Plain `git diff`
+ * already pairs renames by default, so this lists only the deletions that pairing did NOT
+ * absorb -- a moved-and-rewritten module the detector could not pair, which `renamedSince`
+ * answers by detection and therefore misses; the split tolerance reads these paths' content
+ * directly so such a move stays non-novel (#3298 review). The default pairing is load-bearing:
+ * it keeps a split's re-homed hub OUT of this list (paired to its closest part), and passing
+ * `--no-renames` would put it here, making the split's own parts share two statements with
+ * "deleted source" and refusing the very extraction the tolerance exists for.
  */
 export function deletedSourcesSince(repoRoot: string, base: string): string[] {
   const status = git(repoRoot, ['diff', '--name-only', '--diff-filter=D', '-z', base]);
 
@@ -63,7 +63,8 @@ import {
  * - Cost: one unit-lane test file plus two data/reader modules; five git processes for the
  *   merge-base side (merge-base, ls-tree, one cat-file batch for the whole base tree — which is
  *   also where the novelty check reads a deleted source's statements — one rename diff, and one
- *   `-M`-less delete diff listing the sources the rename diff cannot pair), no device. The
+ *   default-pairing delete diff listing only the deletions rename detection did not absorb),
+ *   no device. The
  *   walker memoizes per-file edges per tree and parses each file once per distinct content, so
  *   the base tree pays only for the files the branch changed.
  * - Kill criterion: if two consecutive quarters show no rule ever firing, or