# GRADE COLLAPSE + DEAD PROBABILITY LAYER — diagnosis

**REPORT ONLY. No grade logic, thresholds, or engine code changed** (Kev's instruction).
Two findings. The second one is bigger than the question I was asked.

Data: live Supabase `ledger_entries` (604 rows, all users) + live prod API
`api.vyndr.app`, 2026-07-19 ~22:05 UTC.

---

## FINDING 1 — THE COLLAPSE IS REAL, LIVE, AND STRUCTURAL

Not a thin-slate artifact. Across **604 ledger rows and both sports**:

- **2 distinct grades ever emitted: B and C.** Zero A+, A, A−, B+, B−, C−, D, F.
- **9 distinct confidence values ever emitted:** 63, 57, 55, 52, 47, 45, 35, 25, 20.
- **Confidence ceiling = 63.** It has never exceeded 63 in the recorded era.

Still true **today** (Jul 18 + 19, post every fix, both sports): 4 confidence values
(63/57/52/47), 2 grades.

| Sport | Grade | n | conf min | conf max |
|---|---|---|---|---|
| mlb | B | 276 | 45 | 63 |
| mlb | C | 107 | 20 | 52 |
| wnba | B | 130 | 45 | 63 |
| wnba | C | 91 | 35 | 52 |

### Confidence does NOT determine the letter

| conf | grade | n |
|---|---|---|
| 63 | B | 54 |
| 57 | B | 175 |
| 55 | B | 29 |
| 52 | **C** | 100 |
| 47 | **C** | 14 |
| **45** | **B** | **148** |
| 35 | C | 80 |

**conf 45 → B, but conf 47 and 52 → C.** The mapping is non-monotonic, so the surfaced
`confidence` is not the quantity the letter was derived from. This confirms the
`mlb-grade-degradation.md` "grade↔confidence mismatch" as a *display* artifact: two
different quantities are being shown as if one explains the other.

(At conf 45→B the avg edge is 103; at conf 52→C it is 49 — so the letter tracks the
engine composite/edge, not the displayed confidence.)

### Collateral: the edge scale is still broken and still live

- **311 of 604 rows (51.5 %) have |edge| > 40** — the frontend's `EDGE_BOARD_SANE_MAX`,
  i.e. over half the board's edge is nulled at render.
- **39 rows have |edge| > 100** — impossible as a percentage. Worst: **620**.
- Live today: edges of 140, 180, 220 on Jul 18–19 rows.

`U-deg`'s `projection == 0` leak IS closed (0 since 07-18). The **edge_pct scale is
not** — it remains open and is now quantified.

---

## FINDING 2 — 🔴 THE ENTIRE PROBABILITY LAYER IS DEAD IN PRODUCTION

Found while fingerprinting Arc 1 (U-fp). This is the headline.

### Live fingerprint, `GET /api/snapshot/mlb`, 8 graded props

| Field | Present |
|---|---|
| `projection`, `confidence`, `book_odds`, `fair_odds`, `takeable`, `devig_method`, `alt_lines` | **8 / 8** |
| **`p_win`** | **0 / 8** |
| **`kelly`** | **0 / 8** |
| **`ev_pct`** | **0 / 8** |
| **`model_odds`** | **0 / 8** |
| **`value`** | **0 / 8** |

**Control:** `alt_lines` is present 8/8 and is Desk-gated in `tierGating.js:55`, which
proves the payload is **not** being tier-stripped. These fields are genuinely never
computed — not hidden.

### Root cause — a one-line sport gate, and an S46 fix that was only half-applied

`analyzeViaEngine1.js:509` feeds the estimator from `meta.gameLogs`:

```js
const est = estimateProbability({ gameLogs: meta.gameLogs, line: prop.line, ... });
```

`meta.gameLogs` comes from `computeFeatures.js:173-181` → `gameLogService.getGameLogs`.
And `gameLogService.js:21-26`:

```js
function pythonPath(sport) {
  switch (sport) {
    case 'nba':  return '/stats/last-n';
    case 'wnba': return '/wnba/stats/last-n';
    default:     return null;      // ← MLB exits here
  }
}
```
with `getGameLogs` line 31: `if (!path) return null;`

So:
- **MLB** — returns `null` by construction. Never had game logs on this path.
- **NBA/WNBA** — hits the Python stats service, which is **offline in prod** (documented
  in CLAUDE.md; degrades to null).

⇒ `meta.gameLogs` is `[]` for **every sport in production** ⇒
`estimateProbability` returns `{p_over: null, reason:'insufficient_data'}`
(`probabilityEstimator.js:55-57`) ⇒ `pWin` is null ⇒ **every field guarded by
`if (pWin != null)` is skipped**: `p_win`, `kelly`, `model_odds`, `ev_pct`, `value`.

**This is the S46 bug, second location, never fixed.** CLAUDE.md records that
`gameLogService.getGameLogs` being NBA/WNBA-only starved MLB, and that the fix was an
MLB branch in **`featureCache.gameLogFeatures`**. That fixed the *feature* path — which
is why `projection`, `confidence`, and grades still work. The **estimator path was never
given the same branch**, so it has been silently dead the whole time.

### What this actually breaks

1. **EV — the Model Train's entire ranking signal — does not exist in production.**
   Arc 1 shipped `ev_pct` and it has never once been computed on a live prop.
2. **Hero v2 is non-functional.** `pickHeroProp` requires a finite `ev_pct`
   (`heroPropService.js:84`), so the EV loop matches **nothing** and always falls through
   to the "most recent graded read" fallback. Live proof: `/api/hero-prop` returns
   `"is_recent": true` — the fallback path, every time. The hero has not been an EV pick
   since the day it shipped.
3. **Quarter-Kelly is dead** — same `pWin` dependency (`analyzeViaEngine1.js:516-520`).
   This is a **promise-audit issue**: Kelly sizing is sold on the pricing page and
   `PROMISE-AUDIT.md` lists it as BUILT. It is built and never runs.
4. **The "value triplet" is a duet live** — `book_odds` + `fair_odds` render;
   `model_odds` is always absent.
5. **`value` is never true**, so the VALUE marker can never light up.

### Why this reframes the whole train

- **C-led would persist a column of nulls.** Do not build EV persistence until EV exists.
- **G-a's `EV_FLEX_THRESHOLD` would gate on a permanently-null value.** With
  `EV_FLEX_ENFORCE=0` (Kev's ruling) this is harmless today — but had we enforced it,
  the flex band would have been cut to **zero**, because `ev_pct >= 4` can never be true.
  The ruling to ship it disabled accidentally prevented an outage.
- **S-b (rank board on EV)** would rank on nulls.

---

## RELATIONSHIP BETWEEN THE TWO FINDINGS

They are **adjacent, not identical**, and both trace to the same missing input:

- The dead estimator explains **why no probability-derived output exists** (EV, Kelly,
  model_odds, p_win).
- It does **not by itself** explain the B/C letter collapse, because the letter comes
  from engine1's rule-based composite over the *feature vector*, which is alive.
- But they share a root: **the model is running on a partial input set.** One of its two
  probability inputs (the empirical quantile distribution over real game logs) is absent
  for 100 % of props, so whatever spread the composite was designed to produce is being
  generated from the surviving features only.

**The 9-discrete-confidence-values pattern is consistent with a small set of additive
rule hits** — a scorer landing on a lattice rather than a continuum. Confirming exactly
where the letter range compresses requires the engine1/threshold trace, which is the one
open thread in this report.

---

## RECOMMENDATION (no code changed pending Kev's call)

**Re-sequence: fix the dead estimator FIRST — before G-a, before C-led.**

Rationale: it is the cheapest fix on the board (an MLB branch in the estimator's log
source, mirroring the one already written for `featureCache`), and it simultaneously
restores EV, Kelly, `model_odds`, the VALUE flag, and hero v2. Every other Arc 2-5 item
is downstream of it. Building the gate, the persistence layer, or the board ranking on a
null signal is building on nothing.

Suggested order:
1. **Revive the probability layer** (MLB branch + a real NBA/WNBA fallback, since Python
   is offline). Fingerprint that `p_win`/`ev_pct` appear live.
2. **Then C-led** — persist EV that now has values.
3. **Then G-a** — with the flex band still disabled per the standing ruling.
4. **Separately: the grade-range investigation** (engine1 composite + thresholds), which
   may be partly a consequence of step 1 and should be re-measured after it.

Open question for Kev: NBA/WNBA have no free game-log source on this path with Python
down. `espnStatsAdapter.getPlayerGameLog` (Wave 0) already solves exactly this for
`featureCache` — reusing it here is the obvious candidate, and costs no quota.

---

*Diagnosis 2026-07-19. Data + live API. No engine code changed.*