Applying the method that worked for defence to the two factors the code flagged
as still crude.
PLATOON. The flat version is 'lefty versus righty, add a boost', and it failed
the two-part gate for the same reason team-average defence did: it is not the
unit the causal story runs through. The advantage is only worth what THIS
hitter's split is actually worth -- measured on a real hitter, .284 against
left-handed pitching versus .221 against right-handed, a 63-point split, where
the flat factor applied the same six percent to him and to a hitter with none.
Most of the work is sample discipline, and the second rule matters more than
the first. Severity shrinks toward the league split weighted by the SMALLER
side's plate appearances, because a 500-against-40 split is a 40-PA read. And
below a floor it REFUSES outright rather than shrinking, because a
heavily-shrunk severity is indistinguishable from a measured league-average one
and those are different claims -- without the refusal the atom would quietly
assert a league-typical split about every September call-up in the league.
Switch hitters turn out to be the easy case misread as the hard one. He bats
opposite by choice so the direction is never in doubt, but the per-side value of
his swing is a different question and one this sample cannot answer, so he is
unreadable rather than credited with an automatic edge.
PARK DIMENSIONS. Free from statsapi's venue endpoint, which carries fence
distances, roof, turf and elevation outright -- Wrigley returns 355 down the
left line, 400 to centre, 353 to right, at 595 feet. parkFactors holds run
COEFFICIENTS, which structurally cannot express a park that turns outs into hits
without scoring, and that is why the crude park factor failed.
The park join is by the venue the game is ACTUALLY at, carried from the schedule
feed, never inferred from the home team -- neutral-site and international games
break that assumption and they break it silently. A venue with no geometry at
all is absent rather than a park with zero dimensions.
Both tables dated in the primary key. Venue geometry changes rarely but it does
change, and by now that is the default rather than a lesson.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W1sivYNqY2TS5ftykmHBU9
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
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