c50b is sealed where it stands, as a reference sample rather than a candidate.
Its packed construction was judged good — clearing a board from the rim inward
is the experience it proved out — but at 32 of 50 levels it played as one level
fifty times: 体验太单一了，因为基本都是满盘. The note on why it is kept lives at
the top of its module, because the lesson is the useful part.
It was monotonous on a second axis nobody asked about. 环绕 and 花瓣, the two
route families the brief singles out as the good-looking ones, were absent from
it entirely — not by choice but by a crossing threshold. At 1.0 crossings per
cell, 0% of orbits boards pass and 4% of spirals; at 1.2, 84% and 94% do. The
gate meant to answer "交叉点太多" had quietly deleted the families most worth
looking at, so it moves to 1.2 — still half the 2.36 that drew the complaint.
c50c alternates five kinds of level every three to five: packed boards down to
32%, long-route departures to watch, deep locks to solve, small quick boards,
and segments given over to orbits, petals and spirals by name. All six families
appear, no family exceeds 24%, and the plan is 13 segments rather than 9.
Selection learned to ask for variety outright — by family, piece count and
longest drawn route — instead of hoping it falls out of a difficulty score.
Rule bot across all three: 50/50 cleared and zero dead taps everywhere; c50c
sits between the other two on blind rotations and on how much there is to do.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The game has never had a board you simply clear out, and the request for one
turned out to need a construction of its own rather than a denser deep lock.
Filling cells at random can never work: a packed board has nothing that can
move — measured over forty random fills of a 37-cell board, zero pieces free in
all six orientations, every time, because a piece steps to the next cell before
it can leave and on a full board that cell is taken.
So packBoard builds backwards. Start empty, add only a piece that could leave
right now, and the placement order reversed is a removal order — solvability
becomes a property of the construction. Which cell to fill next decides
everything: at random it stalls near half, while filling the most constrained
cell first takes a 19-cell interior to 96% and fills it outright.
The rim is deliberately empty. Those pieces leave first and ask nothing, and
clearing from the rim inward gives a packed board its own difficulty curve
inside one level — the outer cells read easily, and it tightens as it opens.
Two things were tried against the ceiling and failed, and are recorded as such:
depth-first backtracking made it worse on both counts (65-78% filled against
greedy's 89%, at 2000-3000 seconds a board) because recomputing every cell's
legal directions per node spends the budget three levels deep. And the audit's
dead-turn gate could not be trusted here at all — on a packed board its breadth
search truncates, so it certified levels the rule bot then walked through three
blind turns in a row. The pool is filtered by playing it instead: a full pass
takes one second and does not lie.
The campaign is 32 packed levels to 18 deep locks, alternating, with the closing
six at a completely full interior. Same rule bot, both editions: worst blind
streak 1 either way, dead taps zero, and half again as much to do per level.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A crowded board and a deep lock cannot be the same level — at five turns with
eight pieces per orientation, 16 of 18 candidates fail the release gate, because
pieces packed in leave no room for a turn to open two of them. So the campaign
alternates the two instead of ramping one: crowded stretches for the pleasure of
clearing a full board, deep stretches as the variation between them, and the
last four are the fullest boards in the set.
24 crowded, 14 deep, 12 sparse-and-shallow to open on. Density climbs across the
crowded stretches (0.36 → 0.40 → 0.42 → 0.44) since that is the axis left once
depth is spoken for.
select-50 takes --id and --name so this edition is built beside the first rather
than over it; the fifty already played stay exactly as they are.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
