Found by inducing the real job on the server, not by review: the first chunk
wrote, the second failed with 'ON CONFLICT DO UPDATE command cannot affect row
a second time'. A player can legitimately appear in BOTH the batter and the
pitcher feeds — two-way players, position players who pitch, pitchers who bat —
so (sport, season, source_id) collapsed two real profiles into one key and a
single batch hit the same row twice.
Ohtani has a real batter profile and a real pitcher profile. Merging them would
invent one player out of two genuinely different sets of measurements, so role
goes in the primary key rather than one profile winning. Migration 031 applied;
conflict target updated; a two-way case is now a test.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCNgGSt5qvcLxaeQqa7Zpj
The data foundation for the archetype and projection layers, built as the
pattern every sport inherits. Layers 2 and 3 are not touched.
PHASE 0 GATE — both match rates measured live, both 100%. Batters 40/40;
PITCHERS 66/66 across five real rosters (CLE, DET, MIN, NYY, LAD) joined by
MLBAM id against the 713-pitcher Savant feed. Zero honest-absent on identity,
because the join is an integer both systems use natively — and the snapshot
pipeline already stores it per graded row.
SOURCE — five Baseball Savant CSV leaderboards, free and public, pulled with
axios and the CSV parser savantAdapter already runs in prod. pybaseball is
deliberately NOT used: it is an MIT wrapper over these same URLs, and adding it
would reintroduce a Python runtime in a stack where the existing Python service
is already offline. min=1 on every feed, not Savant's default min=q, so the
long tail arrives and OUR minimum-sample gate decides what is thin — explicit
and testable rather than silently dropped upstream.
Measured: 1,354 rows per season (604 batters, 750 pitchers), all five feeds in
about five seconds. Pitcher mechanism includes arm angle, GB/FB/LD, chase and
whiff; batters get exit velo, launch angle, barrel and hard-hit, chase and
z-swing. Handedness rides in free on the movement feed (677 pitchers); batter
handedness stays absent pending a roster join rather than being guessed.
BACKFILL AND REFRESH ARE THE SAME CALL — a full re-pull upserted on
(sport, season, source_id). Idempotent and self-healing: a missed night
self-corrects on the next run, with no incremental who-played bookkeeping to
drift out of sync. At 1,354 rows the simple thing is also the robust one.
HONESTY RULES, each with a test: a metric the feed did not carry is null and
never 0; a thin sample is STORED and flagged rather than dropped or inflated,
because thin and missing are different claims; an unjoined player is stored
with a null player_key and joins later; and if every feed comes back empty the
job REFUSES to write, so a bad night can never blank a good table.
Freshness is treated as a truth property. updated_at on every row, and the
scheduler pages on a failed run AND on silent staleness — a job that stops
being scheduled never produces a failure, so staleness has to alarm on its own.
Never-built is deliberately not stale: different condition, different fix, and
paging on a fresh install teaches the operator to ignore the alarm.
Nightly at STATCAST_HOUR_UTC (default 11 UTC, after every game is final), kill
switch STATCAST=0, and induce-able at POST /api/internal/statcast/refresh with
a freshness probe at /statcast/status — we verify a refresh by running it, not
by waiting for the slot.
Migration 030 applied. Promoted columns for the classification-critical metrics
plus a metrics JSONB carrying every raw field, so Layer 2 can reach something we
did not promote without a re-ingest. Raw per-pitch stays out of Postgres on
purpose: one season is ~0.85 GB against a 500 MB plan ceiling, and it is
re-pullable from the free source if Layer 3 ever needs it.
Pattern documented in docs/MECHANISM-DATA.md for NBA tracking and NFL Next Gen.
Tests 3581 passed / 292 suites, web build exit 0.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCNgGSt5qvcLxaeQqa7Zpj
builtbykev