diff --git a/docs/re/structures/mcol-collision.md b/docs/re/structures/mcol-collision.md
index ad006b69..ae71b3fc 100644
--- a/docs/re/structures/mcol-collision.md
+++ b/docs/re/structures/mcol-collision.md
@@ -128,6 +128,25 @@ clean populations.
 bounding sphere — the same role `REGN`'s section 3 plays. ❔ Array B's layout is
 unread, and the split has not yet been re-run per array to confirm 100 % on A.
 
-**Next step**: separate the two arrays by their start addresses (`0x74` → A,
-A's pointers → B), then re-run the three criteria on A alone. If the reading is
-right they go to 100 %.
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+### ✅ Split by array, and it goes to 100 %
+
+Done. Separating the records by address and re-running the same three criteria:
+
+| | array A (2 509) | array B (6 467) |
+|---|---|---|
+| byte 3 of word 0 == 1 | **100.00 %** | 30.65 % |
+| bytes 0–2 a valid cell index | **100.00 %** | 30.60 % |
+| the record's sphere reaches that cell | **99.92 %** | — |
+
+**Array A is the per-cell record**, exactly as read: cell index `(x, y, z)`, a
+count, a pointer into array B, and a bounding sphere — the same role `REGN`'s
+section 3 plays. Array B is a different record type; its ~30 % is incidental,
+and it is the control that shows A's 100 % is not something any 32-byte block
+would score.
+
+Worth noting the split was crude — "first half by address", giving 2 509 vs
+6 467 rather than an even cut — and A still came out clean at 100 %. A rough
+partition that isolates a perfect population is stronger evidence than a careful
+one that isolates a good-ish population.
+
+❔ Array B's layout is still unread. That is the next thing.
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