Flatten the challenger draw so the same worlds stop coming back

A 3-star held two tickets and a 1-star held none. On a pool this size that is
not a nudge, it is the shape of the draw. Measured against the live catalog:
3-star worlds absorbed 57% of the graphic draw from 65 of 163 eligible worlds,
46% of atmosphere from 13 of 43, and 75% of interaction from 15 of 25. The
reviewer's report that the same worlds keep returning is exactly what a rating
multiplier does to a corpus whose thinnest tier holds 25 worlds.

Now a 3-star draws level with a 2-star, and a 1-star draws at half rather than
not at all. Excluding a marginal keep made rating do a job breadth already does
properly: breadth still removes a niche world from the pool entirely, which is
the honest way to say "too narrow to challenge an arbitrary build", while a
1-star records "unexceptional" and is still worth showing sometimes.

Effect on the same catalog: the 3-star share falls to 39% on graphic, 30% on
atmosphere and 60% on interaction. That last one is no longer a weighting
artefact, it is simply what the tier contains, since 15 of its 25 eligible
worlds are rated 3.

Compositions get the same treatment; the two ticket functions had the identical
shape and no reason to disagree. Both tests asserted the old policy directly
and now assert the new one.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

skill/scripts/lib/roll-selection.mjs

@@ -96,31 +96,38 @@ function* rank(items, input, idFor = item => item.id) {
     .map(entry => entry.item);
 }
 
-// Two independent exclusions, and either one is enough to hold a world back.
-// Rating grades quality: a 3-star earns a second ticket, a 1-star marginal keep
-// leaves the pool. Breadth says whether a world can serve an arbitrary build at
-// all, so a niche world leaves however good it is, keeping its approval for
-// direct briefs. Breadth was split out of rating because the only way to hold a
-// narrow world back used to be calling it marginal, which made "excellent but
-// narrow" unrecordable and corrupted ratings as a calibration signal.
+// Rating sets how many tickets a world holds; breadth decides whether it draws
+// at all. A niche world leaves the pool however good it is, keeping its approval
+// for direct briefs. Breadth was split out of rating because the only way to
+// hold a narrow world back used to be calling it marginal, which made "excellent
+// but narrow" unrecordable and corrupted ratings as a calibration signal.
+//
+// Two tickets for a 3-star, one for everything else, was too sharp. Measured
+// against the catalog as it stood: 3-star worlds absorbed 57% of the graphic
+// draw from 65 of 163 eligible worlds, 46% of atmosphere from 13 of 43, and
+// 75% of interaction from 15 of 25. The reviewer's complaint, that the same
+// worlds keep coming back, is what a rating multiplier does to a pool whose
+// thinnest tier holds 25 worlds.
+//
+// So a 3-star no longer outdraws a 2-star, and a 1-star draws at half rather
+// than not at all. A marginal keep is still worth showing sometimes: the
+// judgement it records is "narrow or unexceptional", not "wrong", and excluding
+// it entirely made a rating do a job breadth already does properly.
+const RATING_TICKETS = { 1: 1, 2: 2, 3: 2 };
+const ticketsForRating = rating => RATING_TICKETS[rating] ?? 2;
+
 function challengerTickets(pool) {
   return pool.flatMap(concept => {
-    const rating = concept.review?.rating;
-    if (rating === 1 || concept.review?.breadth === 'niche') return [];
-    return rating === 3
-      ? [{ concept, ticket: 0 }, { concept, ticket: 1 }]
-      : [{ concept, ticket: 0 }];
+    if (concept.review?.breadth === 'niche') return [];
+    return Array.from({ length: ticketsForRating(concept.review?.rating) },
+      (_, ticket) => ({ concept, ticket }));
   });
 }
 
 function compositionTickets(pool) {
-  return pool.flatMap(composition => {
-    const rating = composition.review?.rating;
-    if (rating === 1) return [];
-    return rating === 3
-      ? [{ composition, ticket: 0 }, { composition, ticket: 1 }]
-      : [{ composition, ticket: 0 }];
-  });
+  return pool.flatMap(composition => Array.from(
+    { length: ticketsForRating(composition.review?.rating) },
+    (_, ticket) => ({ composition, ticket })));
 }
 
 /**

tests/concept-seed.test.mjs

@@ -314,11 +314,19 @@ describe('concept seed scopes', () => {
       const graphicFirst = picks.find(pick => pick.wellTier === 'graphic');
       counts[graphicFirst.id] += 1;
     }
-    assert.equal(counts.marginal, 0);
-    // Two tickets should put the flagship on top roughly twice as often as an
-    // unrated peer; a generous margin keeps the assertion deterministic-safe.
-    assert.equal(counts.flagship > counts['solid-b'] * 1.3, true,
-      `flagship ${counts.flagship} vs solid-b ${counts['solid-b']}`);
+    // A 1-star draws at half weight rather than not at all. Excluding it made a
+    // rating do the job breadth already does, and a marginal keep records
+    // "narrow or unexceptional" rather than "wrong".
+    assert.equal(counts.marginal > 0, true, `marginal ${counts.marginal} should draw`);
+    assert.equal(counts.marginal < counts['solid-b'], true,
+      `marginal ${counts.marginal} should draw below solid-b ${counts['solid-b']}`);
+
+    // A 3-star no longer outdraws a 2-star. The multiplier concentrated the
+    // draw hard on a thin pool: measured on the live catalog, 3-star worlds took
+    // 75% of the interaction draw from 15 of 25 eligible worlds.
+    const spread = Math.abs(counts.flagship - counts['solid-b']) / Math.max(counts.flagship, counts['solid-b']);
+    assert.equal(spread < 0.4, true,
+      `flagship ${counts.flagship} and solid-b ${counts['solid-b']} should draw comparably`);
 
     // A tier holding only 1-star approvals still yields challengers.
     const onlyMarginal = [
@@ -380,11 +388,15 @@ describe('concept seed scopes', () => {
       const picks = selectApprovedCompositions({ scope: 'direction', key: `stage-weight-${index}`, mode: 'persuade', sourceCompositions: pool, count: 1 });
       counts[picks[0].id] += 1;
     }
-    assert.equal(counts['marginal-stage'], 0, 'a 1-star composition keeps its approval but leaves the draw');
-    // Two tickets should put the flagship first roughly twice as often as the
-    // unrated peer; a generous margin keeps the assertion deterministic-safe.
-    assert.equal(counts['flagship-stage'] > counts['plain-stage'] * 1.3, true,
-      `flagship ${counts['flagship-stage']} vs plain ${counts['plain-stage']}`);
+    // Same weighting as challengers: a 1-star draws at half rather than not at
+    // all, and a 3-star no longer outdraws a 2-star.
+    assert.equal(counts['marginal-stage'] > 0, true, 'a 1-star composition still draws, at half weight');
+    assert.equal(counts['marginal-stage'] < counts['plain-stage'], true,
+      `marginal ${counts['marginal-stage']} should draw below plain ${counts['plain-stage']}`);
+    const stageSpread = Math.abs(counts['flagship-stage'] - counts['plain-stage'])
+      / Math.max(counts['flagship-stage'], counts['plain-stage']);
+    assert.equal(stageSpread < 0.4, true,
+      `flagship ${counts['flagship-stage']} and plain ${counts['plain-stage']} should draw comparably`);
 
     // A pool of nothing but 1-star keeps still yields compositions.
     const onlyMarginal = [