R-280: the band replaced by the test it was standing in for

MEASURABLE = [15,85] proxied for "can this fight move at all". The direct form,
in the units the guard already uses: the spread rate must stand clear of both
ends by more than its own noise. Deliberately blind to the gain -- admitting the
sizes where focus fire clears its noise would make the guard's claim true by
construction. Size is still picked on nearest-an-even-fight.

31 measurable became 38. the_arrears returns at 6.3, and switchboard arrives at
8.1 -- the second largest gain in the artifact, thrown away for being one point
past a round number. Four of the eight carry effects larger than most rows the
band already admitted.

Two of them do not clear their own noise: the_choir has 0.7 points of headroom
and used 0.2, the_stanchion has six and used 0.2. Above-noise falls 31/31 to
36/38 and the bestiary prints 36. That is two measurements reporting no
detectable effect, which the band suppressed by refusing to take them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -187,17 +187,17 @@ check-kits: OK — 25 roles, 10 trades, 218 catalogue items, every kit key resol
 check-lang: OK — en.json, 1018 keys, no leaf/branch collisions
 check-templates: OK — 19 templates compile
 check-behaviour: OK — 76 behavioural tests
-check-scenarios: OK — 13 scenario files, 83 mechanic tags, every skill named resolves against 62 catalogue entries
-check-rollable: OK — 82 rolls across 13 scenario files, every one reachable at 25% or better by somebody present
+check-scenarios: OK — 14 scenario files, 83 mechanic tags, every skill named resolves against 62 catalogue entries
+check-rollable: OK — 82 rolls across 14 scenario files, every one reachable at 25% or better by somebody present
 check-creatures: OK — 102 actor specs across 8 sources, every characteristic, skill, kit key, talent, species and style resolves, no duplicate keys
 check-powers: OK — 41 powers classified, 2 wired and each one measurably changes its fight, 14 recorded as beyond the harness with a reason, 25 not fight rules
 check-anatomy: OK — 5 body plans, 36 locations, d20 complete in both modes, every location drawn, every kind handled and destructible, 20 plan changes carried 432 wounds with their severity intact, 1 flyer(s) with a survivable landing
 check-lethality: OK — 47 creatures, every one fighting exactly as recorded against the frozen party
-check-focus: OK — focus fire measured against 30 packs, helps in all of them, 30 of them by more than their own noise
+check-focus: OK — focus fire measured against 38 packs, helps in all of them, 36 of them by more than their own noise
 check-firstblood: OK — the first disabling blow is worth 40 points of wipe rate in the four-player cut, 15.4 in the six-a-side line
 check-attackers: OK — three of the four-player cut disable on 11.1% of their attacks or better, and one of them on 0.1%
 check-fight-tail: OK — a fight past 15 rounds wipes the party 1.4x as often in the four-player cut and 2.4x at six a side, and nothing was truncated
-check-cited: OK — 25 cited figures across 13 scenario files resolve against 3 baselines
+check-cited: OK — 25 cited figures across 14 scenario files resolve against 3 baselines
 check-handouts: OK — 4 handouts, the two almanac pages identical in structure and columns, every line 41 miles from clean ground, nothing under 11pt
 check-bestiary: OK — 47 creatures, the document matches the game
 ```

docs/BESTIARY.md

@@ -87,11 +87,11 @@ rule for holding an action. Arranging the party so its best weapon fires last wa
 measured in the simulator and came to nothing distinguishable from noise.
 
 **What you can do is kill them one at a time.** Against a pack, every agent putting
-their attacks into the same creature beats spreading them — in **every one** of the
-30 fights in this book whose outcome was ever in doubt, without exception, and by more
-than the measurement’s own noise each time. It is worth about
-**8 points** of win rate against a pair and
-**11 points** against three or more; the best case in the book is
+their attacks into the same creature beats spreading them — in 38 of the
+38 fights in this book whose outcome was ever in doubt, and by more
+than the measurement’s own noise in 36 of them. It is worth about
+**6 points** of win rate against a pair and
+**10 points** against three or more; the best case in the book is
 3 × Kelpie, which goes 52.0% to 67.1%. Most of that is not the ladder
 above: a creature that is dead stops attacking, and one on half its hit points does not
 attack any less. Held at a fixed pack size the dodge ladder is worth a point or two.

docs/REVIEW_LOG.md

@@ -6492,3 +6492,50 @@ unasked.
 
 **Nothing published quoted the lost row.** The bestiary prints the above-noise count from
 the artifact, so it moved 31 to 30 on its own and says nothing that is now false.
+
+## R-280 — the band replaced by the test it was standing in for
+
+`MEASURABLE = [15, 85]` was a proxy. The question it answered is *can this fight move at
+all* — a rate pinned at 0 or 100 cannot show an effect of any size — and it answered with
+two round numbers. R-279 found it excluding the_arrears by three tenths of a point while
+that row carried a gain of 6.2 at 2.4x its own noise.
+
+**The direct form, in the units this guard already uses:** a fight is measurable if its
+spread-fire rate stands clear of both ends by more than its own seed-to-seed noise.
+
+**It deliberately does not look at the gain.** Admitting the sizes where focus fire happens
+to clear its noise would make this guard's own claim true by construction, which is the
+worst thing a guard can be. Size is still chosen on nearest-an-even-fight, and admission is
+still decided without reference to the effect being measured. The order changed — the row
+is measured first and admitted second, because the noise the test needs is a product of the
+measurement rather than of the scan.
+
+**31 measurable became 38.** the_arrears is back at gain 6.3, and seven others arrive:
+
+| | n | spread | gain | noise |
+|---|---|---|---|---|
+| switchboard | 6 | 86.3% | **8.1** | 1.4 |
+| the_arrears | 2 | 14.7% | **6.3** | 1.5 |
+| nuckelavee | 2 | 8.2% | **5.9** | 0.5 |
+| hollow_man | 6 | 92.2% | **4.6** | 0.8 |
+| supporter | 2 | 4.5% | 2.6 | 0.8 |
+| hedley_kow | 6 | 97.7% | 1.6 | 0.6 |
+| the_stanchion | 2 | 6.0% | 0.2 | 0.9 |
+| the_choir | 6 | 99.3% | 0.2 | 0.4 |
+
+Four of the eight were carrying effects larger than most of the rows the band already
+admitted. **switchboard at 8.1 is the second largest gain in the artifact and the band was
+throwing it away**, because an 86.3% fight is one point past a round number.
+
+**And the honest part: the last two do not clear their own noise.** the_choir has 0.7 points
+of headroom at 99.3% and used 0.2 of it; the_stanchion has six points of room and used 0.2.
+The above-noise count falls 31 of 31 to 36 of 38, and the bestiary now prints 36. That is
+not a regression — it is two measurements saying *no detectable effect*, which is a result
+the band suppressed by refusing to take it. A guard that only records the cases where
+something happens is not measuring, it is confirming.
+
+**What is now weaker, and worth watching.** The hard claim — focus fire helps in every
+measurable pack — is satisfied by gains of 0.2, so it is a weaker sentence than it was when
+the band admitted only contested fights. If it should be a stronger claim, the place to
+strengthen it is the claim, not the admission rule; tightening admission to protect a claim
+is how the band got here.

tools/check-focus.mjs

@@ -58,9 +58,23 @@ const SIZES = [2, 3, 4, 5, 6];
    unstable at 3000 and at 4000, and stable across twenty seeds at 6000. This is --update
    only, so the build pays nothing; re-recording pays about half a minute. */
 const SCAN_RUNS = 6000;
-/* A pack whose spread-fire rate falls outside this cannot move enough to measure, and a
-   row that cannot move is a row that would pass this guard whatever happened to it. */
-const MEASURABLE = [15, 85];
+/* R-280. This was a band, [15, 85], and it was a PROXY for the question that matters:
+   can this fight move at all? A rate pinned at 0 or 100 cannot show an effect of any size,
+   so measuring one is pointless. The band answered that with two round numbers, and
+   the_arrears — 14.2% at the only size worth fighting — was excluded by three tenths of a
+   point while carrying a gain of 6.2 at 2.4x its own noise. A proxy that disagrees with
+   the thing it proxies for is worth replacing rather than tuning.
+
+   So the test is now direct and expressed in the same units as everything else here: a
+   fight is measurable if its spread-fire rate stands clear of BOTH ends by more than its
+   own seed-to-seed noise. That is the actual condition for an effect to be visible.
+
+   IT DELIBERATELY DOES NOT LOOK AT THE GAIN. Selecting the sizes where focus fire happens
+   to clear its noise would make this guard's own claim — that focus fire helps in every
+   measurable pack — true by construction, which is the worst thing a guard can be. Size is
+   still chosen on nearest-an-even-fight, and admission is still decided without reference
+   to the effect being measured. */
+const measurable = row => row.spread - row.noise > 0 && row.spread + row.noise < 100;
 
 const party = PARTY_KEYS.map(k => {
   const found = ROSTER.find(r => r.key === k);
@@ -117,22 +131,25 @@ const pickSize = spec => {
 
 if (UPDATE) {
   const creatures = {};
-  let measurable = 0;
+  let measurableCount = 0;
   for (const spec of NPCS) {
     const pick = pickSize(spec);
-    if (pick.w < MEASURABLE[0] || pick.w > MEASURABLE[1]) {
-      creatures[spec.key] = { n: pick.n, pinned: Number(pick.w.toFixed(1)) };
+    /* Measured first, then admitted or not: the noise this test needs is a product of the
+       measurement, so unlike the band it cannot be decided from the scan alone. */
+    const row = measureAt(spec, pick.n);
+    if (!measurable(row)) {
+      creatures[spec.key] = { n: pick.n, pinned: row.spread };
       continue;
     }
-    creatures[spec.key] = measureAt(spec, pick.n);
-    measurable++;
+    creatures[spec.key] = row;
+    measurableCount++;
   }
   await writeFile(BASELINE, JSON.stringify({
     note: "Generated by tools/check-focus.mjs --update. Do not edit by hand.",
     party: PARTY_KEYS, runs: RUNS, seeds: SEEDS, seedMode: SEED_MODE,
-    measurableBand: MEASURABLE, creatures
+    admission: "spread clear of 0 and 100 by more than its own noise", creatures
   }, null, 2) + "\n", "utf8");
-  console.log(`check-focus: baseline recorded — ${measurable} of ${NPCS.length} creatures measurable, `
+  console.log(`check-focus: baseline recorded — ${measurableCount} of ${NPCS.length} creatures measurable, `
     + `${RUNS} runs x ${SEEDS.length} seeds, seed ${SEEDS[0]} ${SEED_MODE}`);
   process.exit(0);
 }

tools/focus-baseline.json

@@ -13,10 +13,7 @@
     90210
   ],
   "seedMode": "per-creature",
-  "measurableBand": [
-    15,
-    85
-  ],
+  "admission": "spread clear of 0 and 100 by more than its own noise",
   "creatures": {
     "quiet_neighbours_npc": {
       "n": 6,
@@ -94,11 +91,17 @@
     },
     "supporter": {
       "n": 2,
-      "pinned": 4.7
+      "spread": 4.5,
+      "focus": 7,
+      "gain": 2.6,
+      "noise": 0.8
     },
     "hollow_man": {
       "n": 6,
-      "pinned": 92.3
+      "spread": 92.2,
+      "focus": 96.8,
+      "gain": 4.6,
+      "noise": 0.8
     },
     "the_tenant": {
       "n": 2,
@@ -106,7 +109,10 @@
     },
     "the_choir": {
       "n": 6,
-      "pinned": 99
+      "spread": 99.3,
+      "focus": 99.5,
+      "gain": 0.2,
+      "noise": 0.4
     },
     "precedent": {
       "n": 3,
@@ -149,7 +155,7 @@
     },
     "long_walker": {
       "n": 2,
-      "pinned": 0.6
+      "pinned": 0.4
     },
     "auditor": {
       "n": 4,
@@ -186,11 +192,17 @@
     },
     "nuckelavee": {
       "n": 2,
-      "pinned": 8.5
+      "spread": 8.2,
+      "focus": 14.2,
+      "gain": 5.9,
+      "noise": 0.5
     },
     "hedley_kow": {
       "n": 6,
-      "pinned": 97.3
+      "spread": 97.7,
+      "focus": 99.2,
+      "gain": 1.6,
+      "noise": 0.6
     },
     "apple_man": {
       "n": 2,
@@ -201,7 +213,7 @@
     },
     "the_committee": {
       "n": 6,
-      "pinned": 99.9
+      "pinned": 100
     },
     "night_registry": {
       "n": 4,
@@ -244,7 +256,10 @@
     },
     "switchboard": {
       "n": 6,
-      "pinned": 85.9
+      "spread": 86.3,
+      "focus": 94.4,
+      "gain": 8.1,
+      "noise": 1.4
     },
     "the_census": {
       "n": 3,
@@ -269,7 +284,10 @@
     },
     "the_stanchion": {
       "n": 2,
-      "pinned": 5.2
+      "spread": 6,
+      "focus": 6.3,
+      "gain": 0.2,
+      "noise": 0.9
     },
     "the_yield": {
       "n": 2,
@@ -287,7 +305,10 @@
     },
     "the_arrears": {
       "n": 2,
-      "pinned": 14.4
+      "spread": 14.7,
+      "focus": 21,
+      "gain": 6.3,
+      "noise": 1.5
     },
     "the_margin": {
       "n": 5,