diff --git a/docs/agents/database.md b/docs/agents/database.md
index 6a6d64f..9d9a53e 100644
--- a/docs/agents/database.md
+++ b/docs/agents/database.md
@@ -13,10 +13,33 @@
 
 **NEVER** manually create migration SQL files or edit `drizzle/meta/_journal.json`. The journal and snapshots must stay in sync — drizzle-kit manages both. Missing snapshots cause `drizzle-kit generate` to fail with "data is malformed".
 
-- Always use `drizzle-kit generate` (or `drizzle-kit generate --custom` for interactive rename prompts)
+- Always use `drizzle-kit generate` and answer any interactive rename prompts (`"Is X renamed from Y?"`) — do NOT use `--custom` for renames, it copies the previous snapshot instead of diffing, which causes the next run to generate a duplicate migration
 - Snapshot JSON must only contain PostgreSQL-valid fields — do not add `"autoincrement"` (Postgres uses sequences, and invalid fields cause Zod validation failures)
 - After generating, run `drizzle-kit generate` again to confirm "No schema changes" — validates the snapshot chain
 - For destructive migrations (drop/rename), use `IF EXISTS` / `IF NOT EXISTS` guards
+- Some existing FK constraints use Postgres auto-generated `*_fkey` names instead of the Drizzle `*_fk` convention. If drizzle-kit generates `DROP CONSTRAINT "<table>_<col>_<ref>_id_fk"` and it fails with "does not exist", add `IF EXISTS` (via `sed -i` on the SQL file) — a mismatched name is the likely cause
+
+## Canonical vs. Per-Window Tables (Qualifying-Points Sports)
+
+Golf, tennis, and CS2 use a split model to support rolling windows that overlap (e.g., a June and September tennis window both containing Wimbledon 2026 + US Open 2026).
+
+- **Canonical** (real-world identity, shared across windows):
+  - `tournaments` — real-world tournaments (Wimbledon 2026 is one row per sport)
+  - `participants` — real-world players or teams (Djokovic, NAVI)
+  - `tournament_results` — final placements, entered once
+  - `participant_surface_elos` — tennis surface-specific Elo
+- **Per-window** (scoped to a `sports_seasons` row):
+  - `season_participants` — draftable roster for this window; links to canonical via `participant_id`
+  - `season_participant_expected_values` — EV under this window's 4-event set
+  - `season_participant_qualifying_totals` — running QP sum for this window
+  - `season_participant_results` — final placement for fantasy scoring
+  - `event_results` — per-scoring-event placements (derived from `tournament_results` via `syncTournamentResults`)
+
+Enter tournament results at `/admin/tournaments/:id`. The `syncTournamentResults` service (`app/services/sync-tournament-results.ts`) fans out to every window linked via `scoring_events.tournament_id` — each window in its own transaction, so partial failures isolate. A CHECK constraint on `scoring_events` enforces `NOT is_qualifying_event OR tournament_id IS NOT NULL`.
+
+When admin creates a new qualifying event via the events admin page, `createScoringEvent` auto-provisions the matching canonical tournament. When admin creates a new season_participant, `createParticipant` auto-links to a canonical participant by `(sport_id, name)`.
+
+Tennis note: Brackt models tennis as two sports (`Tennis - Men`, `Tennis - Women`). Each real-world tournament becomes two canonical rows. Entering women's Wimbledon does not fan out to men's windows — by design.
 
 ## Scoring Event Dates (Non-Obvious Gotcha)
 
diff --git a/docs/agents/domain-models.md b/docs/agents/domain-models.md
index 222612e..31d9c31 100644
--- a/docs/agents/domain-models.md
+++ b/docs/agents/domain-models.md
@@ -27,8 +27,19 @@ Season status drives UI visibility: draft order shown in `pre_draft`, draft cont
 | Model | Description |
 |---|---|
 | **Sport** | Base sport definition (e.g. NFL, NBA); type is `team` or `individual` |
-| **Sports Season** | A specific season of a sport (e.g. "2024 NFL Season") |
-| **Participant** | An athlete or team that can be drafted |
+| **Sports Season** | A specific rolling window of a sport (e.g. "Tennis June 2026") |
+| **Season Participant** | A draftable roster entry for one sports season — links to a canonical Participant |
 | **Season Template** | Reusable configuration for creating league seasons |
 | **Season Sport** | Junction: links a fantasy season to the sports it covers |
-| **Participant Result** | Final standings/scores for participants at season end |
+| **Season Participant Result** | Final standings/scores for season participants |
+
+## Canonical Layer (Qualifying-Points Sports)
+
+Golf, tennis, and CS2 rolling windows share real-world data via a canonical layer. See `docs/agents/database.md` for the schema split.
+
+| Model | Description |
+|---|---|
+| **Participant (canonical)** | Real-world player or team (Djokovic, NAVI) — shared across windows |
+| **Tournament** | Real-world tournament (Wimbledon 2026) — shared across windows |
+| **Tournament Result** | Final placement in a real-world tournament — entered once at `/admin/tournaments/:id`, fanned out to every linked window via `syncTournamentResults` |
+| **Participant Surface Elo** | Canonical surface-specific Elo (tennis) — read by the tennis simulator |