Completes the diagnosis. Report only; no grade logic or thresholds changed.
The grade is an integer index (GRADE_SCALE, NEUTRAL_INDEX 3) moved by a
flat sum of +/-1.0 and +/-0.5 factor deltas, then clamped and rounded.
grade_thresholds.json is NOT an input mapper in the JS path — engine1
reads it BACKWARDS, taking the letter the index already produced and
looking up that band's midpoint to manufacture `confidence`. So
confidence is a cosmetic re-encoding of the letter: zero information
beyond it, and it can never disagree with it. There is no
data-sufficiency penalty in the live path (the one CLAUDE.md describes is
in mlbGrader.js, which is dead code).
Six of thirteen factors are wired to features nothing populates —
verified: refreshTeamStats has ZERO production callers (so opp_rank_stat
is permanently null, killing a +/-1.0), teamId/season_type/
game_count_in_7d are never passed (gameContext is built as {home_away}
and nothing else), and MLB consistency starves on the same dead
gameLogService path as Finding 2. Also verified: BOTH l20 branches are
delta +1.0 — there is no negative L20 contribution at all.
Arithmetic: an A needs sum >= +4.5; the live maximum is +3.0 (+2.0 on a
back-to-back, and MLB rest_days is 0 most days). D needs <= -1.51; the
live minimum is -1.5 and Math.round(1.5)=2, so it misses by one rounding
tick. Reachable band is index 2..6 = {C-,C,C+,B-,B}, which the adapter's
FOUR_LETTER_MAP (a 3->1 collapse) renders as exactly {C,B} — the observed
output, derived from first principles. Reachable confidences {42,47,52,
57,63} match the live values {47,52,57,63} exactly; C- is truncated by
gradeSlateService keeping the higher-confidence side.
mlb-grade-degradation.md's "25/25 grade<->confidence agreement" is a
TAUTOLOGY, not a validation — confidence is derived from the letter, so
it would report 25/25 even if every grade were wrong.
Recommends feeding the starving factors (restores A/D on merit) and
explicitly REJECTS re-scaling thresholds, which would mint A's without
adding information — every "A" would be a relabelled B.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SmNjJAwEnqHPtXbvSZR8kA
Kev's call: investigate the B/C grade collapse before building. Report
only — no grade logic, thresholds, or engine code touched.
FINDING 1 — the collapse is real, live and structural. Across 604 ledger
rows and both sports the engine has emitted exactly TWO grades (B, C) and
NINE confidence values (63/57/55/52/47/45/35/25/20), ceiling 63. Still
true today on both sports. Confidence does NOT determine the letter:
conf 45 -> B while 47 and 52 -> C (non-monotonic), so the surfaced
confidence is not the quantity the letter came from. Edge scale still
broken: 311/604 rows exceed the frontend's sane cap of 40, 39 exceed 100,
worst 620.
FINDING 2 (bigger) — the entire probability layer is DEAD in production.
Live /api/snapshot/mlb: p_win, kelly, ev_pct, model_odds and value are
absent on 0/8 grades, while alt_lines (Desk-gated) IS present 8/8 —
proving nothing is tier-stripped, they are simply never computed.
Root cause: gameLogService.pythonPath returns null for MLB by
construction and the Python service is offline for NBA/WNBA, so
meta.gameLogs is [] for every sport; estimateProbability returns
p_over null; every field guarded by `if (pWin != null)` is skipped.
This is the S46 bug in a second location — that fix added an MLB branch
to featureCache.gameLogFeatures (which is why grades/projections still
work) but never to the estimator path.
Consequences: EV — the Model Train's whole ranking signal — has never
been computed on a live prop. Hero v2 matches nothing and always falls
through to the recent-read fallback (live /api/hero-prop returns
is_recent:true). Quarter-Kelly, sold on the pricing page and listed BUILT
in PROMISE-AUDIT.md, never runs. The value triplet is a duet live.
Recommend re-sequencing: revive the probability layer BEFORE G-a and
C-led (C-led would persist a column of nulls; G-a's EV_FLEX_THRESHOLD
would gate on a permanently-null value — Kev's EV_FLEX_ENFORCE=0 ruling
accidentally prevented an outage). featureCache:206-226 already has both
adapter branches and is the template.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SmNjJAwEnqHPtXbvSZR8kA
builtbykev