diff --git a/backend/app/routes/scheduler.py b/backend/app/routes/scheduler.py
index 0683afaa..bf547483 100644
--- a/backend/app/routes/scheduler.py
+++ b/backend/app/routes/scheduler.py
@@ -145,6 +145,10 @@ def get_scheduler(_: User = Depends(admin_user), db: Session = Depends(get_db))
             .where(Channel.recent_synced_at.is_(None), followed_channel())
         )
         or 0,
+        # The whole opted-in BACKLOG, deliberately not `run_deep_backfill`'s next-pass selection
+        # (which also wants `recent_synced_at`): the same figure /api/sync/my-status shows the user,
+        # and a channel missing its recent pull is one the same job tick fetches first, not one the
+        # job will never touch. Narrowing it here would under-report work that is genuinely queued.
         "channels_deep_pending": deep_eta["channels_pending"],
         "deep_eta_seconds": deep_eta["eta_seconds"],
         "videos_pending_enrich": db.scalar(