Six contested diffs in the 2.x ledgers have no pin, and the empty rosters read as if none existed (`MD, PHD` goes to whichever rule comes first)

[derek73]

Rationale

_CROSS_RULE_WINNERS pins which rule classifies a contested name, because nothing
else in the suite can see a name change hands: per-rule rosters measure a rule
alone, and the gate total is per-corpus
(mechanisms.md#CROSS-RULE-OUTCOME-PINS). A pure file reorder in the 1.4 ledger
fails that roster and nothing else.

Both 2.x ledger sections are empty, and until now that read as "nothing here
is contested". It is not. Measured 2026-09-03 against the real pinned wheels,
six diffs are admitted by more than one rule, with file order alone deciding
the winner and nothing recording it:

ledger	name	measured diff	rules admitting
2.0.0	田中さん 様.	{family, given, suffix}	2
2.0.0	김민준 박사님	{family, given, suffix}	2
2.0.0	선생님	{family, given}	2
2.0.0	田中さん, 様.	{family, given, suffix}	2
2.0.0	MD, PHD	{suffix, title}	2
2.1.0	MD, PHD	{suffix, title}	2

For contrast, the 1.4.0 ledger has 48 such diffs and 31 pinned rows; 2.2.0 has
none and is correctly empty.

How this surfaced

#497 moved the recorded diff shapes into tools/differential/compare.py as
_RECORDED_DIFFS so a run could verify them. Verifying them found that all four
2.x rows recorded shapes no run produces — 'Nguyen, Van' diffs at no baseline
at all, and 'Jane née and Jones Smith' diffs four roles where three were
recorded. Both were removable rather than correctable, because neither name is
contested at a shape any run makes, so the rows adjudicated nothing.

Deleting them left both 2.x sections empty, which is what exposed this: the
sections were never a statement that nothing is contested, and nobody had
measured whether anything was.

What pinning these needs

Not mechanical. Each winner has to be checked against the winning rule's prose
before it is recorded — a rule that classifies a diff it does not describe is
#372, and it stays green everywhere else. That is the same per-pair judgement
#382's eleven precedes_narrower exemptions each needed, and the CJK four sit in
the glued-honorific neighbourhood that took several review rounds to get right
there.

Note also that a recorded row is only as good as the shape beside it. #497's
whole finding is that a shape nothing measures agrees with itself forever, so
each of these six should be recorded with a shape taken from a run, and
_RECORDED_DIFFS is now the place that holds it and the run is what checks it.

Recompute

Replay main()'s load for the baseline (glob → tier order → shape-to-order →
dedupe on (name, order) → baseline-minimum skip), run compare._run_worker
over the surviving entries, compute each name's diff the way main() does, then
count the rules whose name_regex reaches the name and whose fields are a
superset of that diff. More than one is a contest.

Not in scope

Whether file order picks the RIGHT winner for these six. That is the question
#382 answered for the 1.4 ledger's pairs, and it is a separate argument from
recording what wins today.

[derek73]

Framing correction — the empty sections are a stated position, not an oversight,
and this issue should be read as asking whether that position should change.

The issue body above calls the empty 2.x rosters a gap. The roster's own comment
takes a narrower and more defensible line, and it is worth quoting since it is
the thing this issue is actually questioning:

None of those boundaries is argued about in this file, and this roster pins the
arguments this file makes — so a row is owed when someone argues one, not
before.

That is a real position. _CROSS_RULE_WINNERS is not an inventory of every
contested name — the same comment records that hundreds of corpus names are
reachable by two or more rules in the same tier (301 in the 1.4 tier as of #414,
up from 42), and pins 31. It pins the boundaries the file argues about, because
a pin is only as good as someone having reasoned about which rule should win.

So the question here is not "why were these six left out". It is: now that the
six are measured rather than merely unexamined, does that change what is owed?
Two honest answers:

• No. Nobody has argued a 2.x boundary. Recording a winner nobody has
  reasoned about pins whatever file order happens to produce, which is how a rule
  comes to classify a diff it does not describe (Ledger rules classify diffs they do not describe, and a rule that stops explaining anything is invisible #372) — the failure the roster
  exists to catch, installed by the roster itself.
• Yes, for some. MD, PHD appears in both 2.x ledgers and in the 1.4 ledger's
  argued set already; a boundary argued at one baseline is arguably argued at all
  of them, and the four CJK names sit in the glued-honorific neighbourhood Should file order be allowed to separate ledger rules within a tier? (김, 민준씨 is claimed by whichever of two rules comes first) #382
  spent several rounds on.

The comment now cites this issue at that sentence, so a reader meets the question
where the position is stated. Nothing in the tree presumes the answer.

Also correcting two claims I made while filing this, both wrong and both caught
by measurement:

• I said the 2.x ledgers had no contested name. They have six; that is this
  issue.
• I justified deleting the four rows as "they pinned a one-rule race". Measured,
  13 of the 31 surviving 1.4.0 rows are also one-runner races and are kept
  deliberately — they pin shapes runs actually make, so widening a fields or
  moving a rule hands the name over and the guard says so. The property that
  distinguished the four deleted rows is narrower: no run makes their shapes at
  all. The roster comment states it that way, with a warning not to follow the
  looser reasoning.

[derek73]

Scoping down, not closing — the six contested diffs now carry measured shapes, and no winner.

PR #504 adds a second roster beside _RECORDED_DIFFS: compare._WATCHED_DIFFS, for a diff shape recorded with no winner pinned. The six contests this issue measured are in it:

ledger	name	recorded shape	severity
2.0.0	田中さん 様.	{family, given, suffix}	fatal (contract tier)
2.0.0	김민준 박사님	{family, given, suffix}	fatal (contract tier)
2.0.0	선생님	{family, given}	fatal (contract tier)
2.0.0	田中さん, 様.	{family, given, suffix}	printed, non-fatal (radar tier)
2.0.0	MD, PHD	{suffix, title}	printed, non-fatal (radar tier)
2.1.0	MD, PHD	{suffix, title}	printed, non-fatal (radar tier)

Every run now checks each against the diff it measures, so a shape that moves is reported (MOVED SHAPE / MOVED SHAPE (radar)). What this does not guard is the thing this issue is about: a handover — file order still picks the winner, and only a _CROSS_RULE_WINNERS pin sees a name change hands. Recording a shape without a winner was chosen precisely so the roster does not pin an argument nobody has made (the framing comment above), and the _CROSS_RULE_WINNERS 2.x sections stay empty as a stated position.

So the question here is unchanged: whether a measured-but-unargued contest should be pinned. decisions.md's watched-shapes arc records the decline of pinning them in this bundle and why. The day one of these boundaries is argued, the row moves from _WATCHED_DIFFS to _RECORDED_DIFFS with its winner.

[derek73]

Correction to the table above, after PR #505: 田中さん 様. is now radar tier — its trailing ASCII period put it in the same listing-artifact class as its comma twin, and the 2026-09-01 sweep's criterion had missed the class. Its watched row prints MOVED SHAPE (radar) and cannot fail the run. Two of the four 2.0.0 contests remain contract-tier and fatal: 김민준 박사님 and 선생님.