diff --git a/scripts/validate-grade-fix.js b/scripts/validate-grade-fix.js
new file mode 100644
index 0000000..b929d2a
--- /dev/null
+++ b/scripts/validate-grade-fix.js
@@ -0,0 +1,28 @@
+#!/usr/bin/env node
+// Post-fix re-grade validation (work-order item #4). Fetches the LIVE MLB
+// snapshot and checks the three degradation signatures are gone:
+//   1. projection == 0 count -> expect 0 (the nine vanish; those props refuse)
+//   2. edge_pct continuous, not the {20,60,100,140} degenerate cluster, no 100
+//   3. grade <-> confidence agreement -> expect 25/25 (letter == band(conf))
+// Run: node scripts/validate-grade-fix.js   (needs outbound to api.vyndr.app)
+const https = require('https');
+const BANDS = require('../src/services/python/data/grade_thresholds.json').grade_scale;
+const four = (g) => { const s = String(g||'').toUpperCase(); return s === 'A+' ? 'A+' : (s[0]||null); };
+function bandOf(conf) { const p = conf/100; for (const [k,b] of Object.entries(BANDS)) if (p>=b.low && p<=b.high) return k; return null; }
+function get(url) { return new Promise((res,rej) => https.get(url,(r)=>{let d='';r.on('data',c=>d+=c);r.on('end',()=>res(JSON.parse(d)));}).on('error',rej)); }
+(async () => {
+  const d = await get('https://api.vyndr.app/api/snapshot/mlb');
+  const g = d.grades || [];
+  const proj0 = g.filter(x => x.projection === 0 || x.projection == null).length;
+  const edges = g.map(x => x.edge_pct).filter(v => v != null);
+  const has100 = edges.includes(100);
+  const distinctEdges = [...new Set(edges)].sort((a,b)=>a-b);
+  let agree = 0;
+  for (const x of g) { const b = bandOf(x.confidence); if (b && four(b) === four(x.grade)) agree++; }
+  console.log('=== AFTER (post-fix) — live MLB snapshot ===');
+  console.log('updated_at:', d.updated_at, '| grades:', g.length);
+  console.log('1. projection==0/null:', proj0, proj0 === 0 ? 'PASS' : 'FAIL (expect 0)');
+  console.log('2. edge_pct distinct:', distinctEdges.length, 'values; contains 100:', has100, (!has100 && distinctEdges.length > 4) ? 'PASS' : 'CHECK');
+  console.log('   values:', distinctEdges.slice(0, 20));
+  console.log('3. grade<->confidence agree:', agree + '/' + g.length, agree === g.length ? 'PASS' : 'FAIL');
+})().catch(e => { console.error('validation error:', e.message); process.exit(1); });
diff --git a/specs/audit-data/mlb-grade-degradation.md b/specs/audit-data/mlb-grade-degradation.md
index dd2f142..b07bc51 100644
--- a/specs/audit-data/mlb-grade-degradation.md
+++ b/specs/audit-data/mlb-grade-degradation.md
@@ -1,37 +1,66 @@
-# MLB Grade Pipeline Degradation — Backend Finding (2026-07-17)
+# MLB Grade Pipeline Degradation — FIXED (2026-07-17)
 
 Source: phone-audit P1-7 (broken edge board) + P2-9 (B grades at 45% confidence).
-Diagnosed against LIVE `GET /api/snapshot/mlb` on 2026-07-17. This is a BACKEND
-grading/feature-pipeline issue, NOT a frontend display bug. The frontend guards
-(sane-edge cap, statAbbrev) are damage control, not the fix.
+Diagnosed against LIVE `GET /api/snapshot/mlb` on 2026-07-17. Backend grading
+bug, fixed at the source in the generic grade path (`engine1` +
+`analyzeViaEngine1`), which grades EVERY sport.
 
-## The evidence (25 live MLB grades)
-- **projection == 0 for 9/25.** The model has no projection reference for a third
-  of props — a degraded feature path (the S58 insufficient-data refusal should
-  have caught these; instead they graded with projection 0).
-- **edge_pct on a broken scale.** Distinct values {20, 60, 100, 140}. A real
-  prop-market edge is single-digit %, never past ~40. These are not a market edge
-  (frontend now shows them absent — slateAdapter EDGE_BOARD_SANE_MAX / EdgeCell).
-- **grade <-> confidence mismatch on 25/25.** Every grade's letter disagrees with
-  its own surfaced `confidence` vs `grade_thresholds.json`:
-    - B shown at confidence 55 -> 55 is the B- band (55-59), not B (60-65).
-    - Systematic ~5-point (one sub-tier) gap on every prop.
-  The surfaced `confidence` is NOT the probability that derived the letter.
+## Before (25 live MLB grades, degraded)
+- **projection == 0 for 9/25** — graded on a zero projection.
+- **edge_pct quantized to {20, 60, 100, 140}** — the 100s were the proj=0
+  degeneracy `(line - 0)/line = 100%`.
+- **grade ↔ confidence mismatch** — 10/25 disagreed even at the 4-letter level
+  (25/25 vs the stricter 11-step bands).
 
-## Likely root cause (to investigate, not yet fixed)
-1. `confidence` field is post-`apply_data_sufficiency_modifier` (bayesian.py),
-   while the grade letter was assigned from the PRE-penalty prob -> the two
-   disagree by one sub-tier on every prop. Either surface the same value, or
-   re-letter from the penalized confidence. Decide which is the source of truth.
-2. projection==0 for 9/25: the MLB feature/projection path is feeding 0 instead
-   of refusing (S58 `insufficient_data`). Trace `projectionFor` for MLB props;
-   projection 0 also breaks `computeEdge` (=> the 20/60/100/140 garbage).
+## Root causes + fixes (commit `888d103`)
+1. **projection=0 bypassed the refusal gate.** `projectionFor` returned
+   `l5_avg` even when 0 (finite → the `== null` gate passed it). FIX: a
+   non-positive reference is not a projection — `projectionFor` skips it and
+   falls through to the next POSITIVE reference (l5 → l20 → per_90 → xg); when
+   none is positive it returns null and the read REFUSES (`insufficient_data`).
+   The gate also gained an explicit `> 0` guard — the invariant is structural.
+2. **edge_pct.** Formula was already `(model - line)/line` (the intended
+   semantics); the {100} cluster was purely the proj=0 degeneracy. With fix 1
+   those refuse. Main-line edge now reuses the VALIDATED projection so edge and
+   the persisted `projection` can't diverge.
+3. **confidence/letter split.** `engine1.GRADE_TO_CONFIDENCE` was hand-rolled
+   and drifted a full sub-tier low (B → 0.55, which `grade_thresholds.json`
+   calls B-). FIX: confidence is now DERIVED from each grade's band MIDPOINT in
+   `grade_thresholds.json` — one source of truth. Applying the threshold table
+   to any grade's displayed confidence resolves back to the same letter (proven
+   for all 11 grades in `tests/unit/mlbGradeDegradation.test.js`).
 
-## Do NOT
-- Do not re-letter or shift thresholds on the frontend (would hide the bug).
-- Do not "fix" edge display by rescaling 140 -> 14 (guessing the scale is its own
-  fabrication). The number must come out of the pipeline correct.
+## Blast radius (commit `9fc4edf`) — work-order #6
+The degraded grades (projection=0 → `model_value = 0`) are already settled in
+the append-only `ledger_entries` and are NOT deleted. Functional marking:
+`getModelAggregate` now filters `.gt('model_value', 0)` on the settled AND
+pending queries — the rows stay in the ledger but leave the public model record
+(their hit/miss is noise, not skill). Post-fix no new such row can be written.
 
-## Frontend already shipped (honest guards)
-- Leaderboard stat labels: `web/src/lib/statAbbrev.js` (raw snake_case -> SB/ER/TB).
-- Edge board: impossible |edge|>40 rendered absent AND excluded from ranking.
+**Exact count NOT queryable from the dev box** (`*.supabase.co` is unreachable
+here — curl 000; only `vyndr.app`/`api.vyndr.app` resolve; no `VYNDR_INTERNAL_KEY`
+locally). Proxy signal: 9/25 (36%) of the current live slate. For the precise
+figure, run in Supabase SQL:
+```sql
+SELECT count(*) FILTER (WHERE outcome IS NOT NULL) AS settled_degraded,
+       count(*)                                    AS total_degraded
+FROM ledger_entries
+WHERE user_id IS NULL AND model_value = 0;
+```
+
+## Other sports — work-order #5
+NBA/WNBA/soccer grade through the SAME `analyzeViaEngine1` → `engine1` path
+(`gradeSlateService` does not branch by sport; `mlbGrader.js` is dead code). So
+they SHARE the disease and are fixed by the same commit. They rarely grade in
+prod today (stats service offline off-season → refuse anyway). No separate fix.
+
+## Live validation — work-order #4
+The fix deploys immediately, but the SNAPSHOT only re-grades on the full cron
+(UTC hours 14,19,22,1,3). Run after the next 14:00 UTC snapshot post-deploy:
+```
+node scripts/validate-grade-fix.js
+```
+PASS criteria: projection==0 count → 0; edge_pct no longer contains 100 and is
+not the four-value cluster; grade↔confidence agreement 25/25. The before-state
+(this file's "Before") is the diff baseline; the script's output is the
+fingerprint.