From 3aa8d50644d043efb052926fd675f9639bbbf095 Mon Sep 17 00:00:00 2001
From: Prad Nukala <prad@sonr.io>
Date: Mon, 24 Aug 2026 19:24:28 -0400
Subject: [PATCH] api: document learned-topic drill rule

---
 api/README.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/api/README.md b/api/README.md
index 34af509..33e6075 100644
--- a/api/README.md
+++ b/api/README.md
@@ -27,6 +27,11 @@ A problem's first-ever log enters at `+2` regardless of result. Stage names
 the NEXT review's interval. All dates are ET calendar strings anchored at
 noon UTC (`src/srs.ts`) — never raw `Date` math.
 
+Blind drills draw only from topics **already learned**: scheduled in an
+earlier week (the current week's optional pool is reserved for Saturday's
+gate) and with at least one core problem on the ladder — a skipped learning
+day never feeds drills just because its calendar week lapsed.
+
 ## Routes
 
 | Route | Auth | Purpose |