Wave 5B: Pitcher Arsenal via Baseball Savant (Statcast)
D4 — build the FREE Baseball Savant adapter for pitch-level identity
(mix / velo / usage% / whiff%), the missing layer statsapi doesn't carry.
- savantAdapter.getPitcherArsenal(id|name) — normalizes two public Savant
CSV leaderboards (csv=true, NO parsing dependency): pitch-arsenal-stats
(usage% + whiff% + K%) + pitch-arsenals avg_speed (velo). League-wide,
cached 24h + in-memory mirror, indexed by MLBAM id. Defensive: null on any
unrecognized shape; a missing velo/whiff is ABSENT (null), never 0.
Injectable (fetchImpl/statsCsv/veloCsv/resolveId) → tests hit no network.
Live endpoints VERIFIED (200, exact columns) from the sandbox.
- GET /api/stats/pitcher/:name/arsenal (stats.js) + Next proxy. MLB-only;
an error/miss returns { found:false } so the card self-hides honestly.
- PitcherArsenal.tsx (+ barrel) — the mockup's PITCHER IDENTITY strip:
pitch mix % + velo + whiff%, mono/tabular, ranked by usage, sharpest-whiff
pitch highlighted green. Self-hides (heading included) when arsenal absent.
Mounted on the MLB player profile (a pitcher surface). Context, not a
graded market value.
- Tests: savantAdapter (fake CSV → ranked arsenal; unknown shape/blank cells
→ absent not 0; name→id resolve) + PitcherArsenal source locks (self-hide,
mono/tabular, em-dash-not-zero). +2 suites / +17 tests (3012 → 3029).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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