RBI is power TIMES opportunity. The same swing drives in one run or three
depending on who is on base, and a hitter batting with the bases empty cannot
drive anyone in however hard he hits it. Every context-free model of RBI here
has failed, and the failure kept being read as 'skill inputs don't work for
RBI' when the truth was that we were modelling half the stat.
Both halves are free from statsapi.mlb.com, which we already call for game
logs, schedules and probable pitchers. No new provider, no key, no quota.
RUNG 1, batting order: schedule?hydrate=lineups returns homePlayers and
awayPlayers as ORDERED arrays of nine, and the order IS the batting order --
index 0 is the leadoff hitter. That single fact gives CATALYST its identity
and supplies lineup-position context for every context-dependent stat.
RUNG 2 turned out cheap, which the cheapest-first rule did not expect. It
looked like it would need play-by-play reconstruction across a season; statsapi
serves situational splits directly, so 'how often does this hitter bat with
runners to drive in' is ONE call per player rather than one per game. Measured
on a real hitter: 87 plate appearances with runners in scoring position
producing 25 RBI, against 302 with the bases empty producing 17. That ratio is
the opportunity half of the stat and it is the thing no amount of exit velocity
can tell you.
Both tables are dated in the primary key. statcast_aggregates was built
upsert-in-place and that silently made every backtest leak the games it was
predicting; a lineup is worse still, because it is a PRE-GAME fact that changes
by the hour, so an in-place table would overwrite what we knew at grade time
with what turned out to be true.
Absent stays absent throughout: no lineup posted is an empty slate rather than
a guessed order, a short lineup records fewer slots rather than padding to
nine, and a hitter with no splits is null rather than a zero RISP share --
which would assert he never bats with runners on, a strong claim and usually a
false one.
Wired into the snapshot best-effort, so a context failure can never break the
pipeline it rides in. The three pre-registered theories are now marked
input-ready rather than input-blocked: DRIVER's power x runners-on and power x
lineup-position, and CATALYST's speed x on-base x power-behind. They are
sample-blocked from here, and the proofs run under native cumulative
correction as sample accumulates -- ingesting is not proving.
Counter and frozen clusters byte-identical. 4,250 tests green (338 suites);
web build exit 0.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W1sivYNqY2TS5ftykmHBU9
builtbykev
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