Files
vyndr/tests
builtbykev 74cf1ce974 Robust bias established; low-parameter correction replaces isotonic
PHASE 0 — sample-limit truth on record: on 19 dates BOTH stability
instruments are underpowered. LODO power 0.014-0.093 (best 0.337 across
every k tried); deploy CIs rest on 2-4 date clusters, where a
cluster-robust interval has ~1 df. This is the SAMPLE, not a fixable
instrument, and the gate-refinement loop stops here. Runs corrected: its
DATE-DRIVEN label was an artefact of the coin-flip ruler (2 reversals in
3 drops never cleared cutoff 2) -- it is an ordinary no-fittable-map
refusal.

PHASE 1 — the bias is ROBUST, tested model-free and map-free with a
date-block bootstrap. Pooled over-prediction rises monotonically -0.0076
/ +0.0428 / +0.0963 / +0.1589 / +0.2451 across deciles from 0.5 to 1.0,
sign stability 0.9946 over 17 date blocks, and 4 of 4 stats replicate
(bar was 3). Also visible: realized rate PLATEAUS at 0.65-0.68 from p=0.7
upward -- the 0.9+ bucket (0.6624) does no better than the 0.8-0.9 bucket
(0.6841). The model has no high-confidence reads, only high-confidence
numbers.

PHASE 3 — Platt, two parameters over the whole curve, shrunk toward
identity by fit-date count. Validated as a NEW estimator vs RAW with
date-block CIs:

  hits         a=0.406 shrink 0.565  0.2626 -> 0.2540  CI [-0.0112,-0.0069]  DEPLOY
  total_bases  a=0.472 shrink 0.333  0.2490 -> 0.2429  CI [-0.0062,-0.0059]  DEPLOY
  rbi          a=0.775 shrink 0.231  0.2011 -> 0.2007  CI [-0.0007, 0]       REFUSE
  runs         a=-0.032                                                      REFUSE

A GUARD THE FIRST RUN NEEDED: runs fitted a = -0.032. A non-positive
slope inverts the forecast rather than flattening it, and near zero the
curve collapses to a constant predicting the base rate for everything --
which LOWERS Brier while destroying all resolution. It would have scored
as a win while making the product worthless. MIN_SLOPE now refuses it by
name, with a test.

STATED PLAINLY: on the identical held-out rows isotonic BEAT the
low-param on hits (+0.0028) and rbi (+0.0042) and tied on TB. The swap is
a CAPACITY JUDGEMENT, not a measurement -- the window spans 2-4 date
blocks and that is exactly what a flexible map produces when it captures
structure shared by fit and eval. Labelled as a judgement.

PHASE 4 — hits and total_bases serve the correction, basis
direction_robust_magnitude_provisional (direction bootstrap-robust,
magnitude thin-sample and shrunk). rbi is WITHDRAWN to raw -- it was
deployed on isotonic at ced4042 and the low-param does not beat raw.
runs stays raw. Auto-demotion still armed.

PHASE 5 — the standing finding, stated hard: across 18 archetype slots on
three stats, calibrated p_win separates within archetype NO BETTER than
raw. Every slot is one band indistinguishable from its base rate, zero
show lift. Per-archetype separation is not coming from calibration; it
comes from proven factors or it does not exist. Five orders of
calibration have delivered what they can -- honest numbers on two stats --
and nothing on the question the grade product turns on.

p_win never mutated; no Bonferroni slot; the robust-claim test ran before
any calibrator was built and could have ended the session at Phase 2.
Counter and frozen clusters verified file-by-file, including calibration.js
and calibrationService.js, both untouched and simply off the serving path.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W1sivYNqY2TS5ftykmHBU9
2026-08-06 23:20:05 -04:00
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