Step 0 input check: stop before wiring opportunity, and why

READ-ONLY. Live grade path byte-identical -- no layer wired, no threshold
moved, no challenger added, no holdout run.

INPUTS ARE 100% POPULATED (n=80 real MLB props, through the grader's own
path): ab_per_game, rest_days, l5_avg, l20_avg, l10_stddev and
game_count_in_7d all 100%; opp_rank_stat 65% overall and 0% on
stolen_bases. So there is no honest-degradation problem to solve.

FOUR FINDINGS THAT STOP THE WIRING, three of which would have made the
work unmeasurable or wrong:

1. THE PREMISE IS WRONG. There is no built opportunity layer to connect.
   ab_per_game is consumed in exactly one place -- analyzeViaEngine1:379,
   which renders "4.3 AB/G" on the grade card. engine1 has NO opportunity
   or usage factor at all. A projected opportunity was never built;
   building one is construction, not connection.

2. THE INPUT IS THE WRONG SHAPE. ab_per_game = season atBats/games. It is
   a per-player CONSTANT (measured: varies for 3 of 20 players, and those
   cannot be legitimate since the value can't depend on stat_type), so it
   can only move all of a player's props together, never separate them.
   And it is collinear with the projection: l20_avg = seasonTotal/games,
   the SAME denominator, so l20_avg already embeds opportunity
   multiplicatively. Adding it additively double-counts.

3. THE REAL INPUT DOES NOT EXIST. depthChartService returns battingOrder:
   null for MLB ("the one lineup slot the free schedule feed exposes") and
   PropLine /context carries lineup_confirmed as a BOOLEAN, not the order.

4. ARCHITECTURE: wiring it into engine1 would be unmeasurable BY THIS
   ORDER'S OWN TEST. Step 2 proves reliability and resolution, both
   measured on p_win. engine1 factors move the grade LETTER and never
   touch p_win. The layer belongs in probabilityEstimator, which already
   adjusts on opp_rank_stat, home_away and a consistency pull.

SEQUENCING IS ALSO STALE: challengerProjection (arch-v1) is already live
with archetype, matchup (platoon) and environment (park) axes, writing
p_win_challenger to the ledger. Step 2 of the order's sequence is partly
done -- and the harness this order needed already exists.

RECOMMENDED INSTEAD, as its own order: an `opportunity` axis on that
harness driven by DRIFT, not level -- recent AB/G (last 5) over season
AB/G. A deviation is not collinear the way the level is. Per-game atBats
is present in the statsapi log rows but MLB_LOG_FIELD never maps it, so it
is a small contained BUILD, which is why it gets its own order. Honest
caveat carried forward: it is still a proxy, not tonight's opportunity.

PROBE BUG RECORDED: the first run reported 0% for every feature including
l5_avg, on a pipeline that had just graded 365 props -- impossible, so the
probe was wrong. getFeatures takes camelCase and returns { features: {} };
I passed snake_case and read the top level. Fixed to call
computeFeaturesForProp. Same class as the earlier silent-false harness: a
measurement that makes working code look broken invites you to "fix"
something that was never broken.

Gates: 4,059 tests / 325 suites green; next build exit 0.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QJs13VsyiSKYQP6rj3NNmc

specs/MASTER-PLAN.md

@@ -78,6 +78,7 @@ multi-book data.
 | **soccer** | **settles** — ~15 competitions, 30d | "grades into a void" is a **$19/mo Pro-tier** problem, not a data problem |
 | **CLV + results feeds** | `/odds/closing` + `/movement` **redacted**; `/results` **403 `required_tier: hobby`**; `/exports/resolved-props` **403 `required_tier: pro`** | **verified on our keys** — plain tier exclusion, not a key or plan fault. **$9/mo** buys CLV + steam + results; **$19/mo** adds the 90-day settlement export |
 | **books SERVED** | 5 → **13**; props rendered **546 → 2,780** (5.1×); mean **4.22** books/prop | **AGGREGATOR widening is LIVE.** Of 2,234 newly-visible props, **31.2% carry a real non-DFS price**; **68.8% are DFS-only** — shown, tagged, never a market |
+| **opportunity layer** | **NOT BUILT** — `ab_per_game` is display-only; engine1 has no usage factor; MLB batting order unavailable in every wired source | Step 0 stopped before wiring. Recommended instead: an `opportunity_drift` axis on the EXISTING `challengerProjection` (arch-v1). See `specs/connect-opportunity-step0.md` |
 | **MLB board size** | **7 → 365 graded props** (52×) in 114s | the 25-cap discarded 95.7% of the slate. Raised to 500 on measured cost. Refusals were **43.8% deliberate policy suppression**, not a data gap |
 | **model input** | **byte-identical** — 546 gradeable props, `v1_first_book` | `MODEL_BOOKS` gate in `dedupeProps` + `indexOddsProps`. Lifts only on the re-run |
 | **accrual clock** | **sequential, post-completion** | see §11. Pre-completion data does not count and is never pooled |