# `[2026-08-27]` The corpus mix was specified in a unit the optimiser never sees

Run 3's recipe specified its mix as **context shares** — dialogue 45.8% / kvasir 38.0% /
fireball 16.2% — and was approved, built and trained on that basis.

**As TRAINED the gradient was 24.2% dialogue and 75.8% prose.**

    effective_mix, adapter provenance.json, LOSS shares
        kvasir     0.5310
        fireball   0.2271          prose     75.81%
        c2-logs    0.0861
        cwm        0.0763
        bluemoon   0.0796          dialogue  24.20%

Not a reinterpretation — **the trainer wrote both numbers into the same manifest and nobody
read the second one**, across three runs.

## The mechanic

F2/F3/F4 mask loss off dialogue turns while leaving their context in place. So **the harder
the dialogue filters work, the more prose-dominant the gradient becomes.** Every mix ruling
was made in the wrong unit.

## Why it survived review

infra-ops set kvasir's subset to 38.0% *of context* because that is the unit the recipe stated
a share in, and because fireball's 12% landed exactly on context — which was read as
confirmation the recipe meant context throughout. It did. **The specification was in the wrong
unit and it was matched faithfully**, which is a worse failure mode than an arithmetic error
because every check agreed with it.

## The fix — a RENAME, not a reordering

Harness commit `dd5a12e` (eitri-smithy). Both numbers were already printed, adjacent, with
context first — and that was enough for three runs of people reading the wrong one. Demoting
context would not have stopped a fourth.

    [mix]   LOSS share is what the optimiser sees. ctx share is a memory budget, NOT the mix.
    [mix]   kvasir      loss 0.5310   [memory budget: ctx 0.3800]

Calling it a *memory budget* makes "the mix is 38% kvasir" a sentence someone has to actively
mis-say. Found by brokkr-smithy-dev's CPU arm after the run-3 gate.

See also [[2026-08-27-dose-response-entanglement]] — the wedge this finding produced was
consistent with four separate failures and was still not the whole story.