One generator, so a citation names one fight (R-265)

tools/playthrough.mjs exists to show a reader why a measured number is what it is. I cited it to another session — read seed 2, see the wipe the 45% row is made of — and the reproduction failed in front of them. They reported different outcomes at both seeds and guessed the cause correctly from outside: the two tools were not drawing from the same stream. They were not. simulate.mjs used a private mulberry32 makeRng; playthrough.mjs had its own LCG written to look like it. Both deterministic, both reproducible alone, and "seed 2" named a different fight in each — which breaks the only thing the tool is for. Its own comment claimed a seed here names the same fight there. check-focus carried a third copy of that LCG, so the two guards described the same game with different dice. makeRng is exported and both files use it. A playthrough seed is now exactly the first fight of simulate.mjs --seed <n>: --runs 1 --seed 2 and the playthrough give 9 rounds, 4 of 4 down, 1 dead, both. The other half was my citation rather than the code: the command I sent omitted --mode, so it plays both targeting arms and prints two fights. They read the last line, I quoted the first. The summary line now names the arm. check-focus re-recorded under the shared stream; figures move a point or two. What it buys is that the bimodality analysis now reproduces the published means exactly — 2.31, 3.03, 0.40, 0.42 against the four rows CLEAN GROUND publishes. Under the old LCG it agreed to within a decimal, which looked like corroboration and was two experiments landing near each other. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-13 01:11:41 +01:00
parent 796bb7df73
commit 8627fa3536
8 changed files with 201 additions and 146 deletions
@@ -31,7 +31,7 @@ import { existsSync } from "node:fs";
 import path from "node:path";
 import { NPCS } from "./content.mjs";
 import { ROSTER } from "./roster.mjs";
-import { runFight, seedFor } from "./simulate.mjs";
+import { runFight, seedFor, makeRng } from "./simulate.mjs";

 const ROOT = path.resolve(path.dirname(new URL(import.meta.url).pathname.replace(/^\/([A-Za-z]:)/, "$1")), "..");
 const BASELINE = path.join(ROOT, "tools", "focus-baseline.json");
@@ -67,7 +67,10 @@ const party = PARTY_KEYS.map(k => {

 /* One generator per arm, derived from the creature's own key, so inserting a creature
   cannot perturb its neighbours — R-252, learned the hard way. */
-const rngFor = seed => { let s = seed >>> 0; return () => ((s = (1664525 * s + 1013904223) >>> 0) / 4294967296); };
+/* R-265: the harness's own generator, not a second one of the same shape. This file used
+   to roll its own LCG, so the two guards described the same game with different dice and
+   no figure here could be reproduced from simulate.mjs. */
+const rngFor = makeRng;
 const winRate = (foes, targets, seed) => {
  let won = 0;
  for (let i = 0; i < RUNS; i++) {
@@ -20,66 +20,66 @@
  "creatures": {
    "quiet_neighbours_npc": {
      "n": 6,
-      "spread": 47.4,
-      "focus": 55.7,
-      "gain": 8.3,
-      "noise": 2.5
+      "spread": 47,
+      "focus": 54.9,
+      "gain": 7.9,
+      "noise": 2.7
    },
    "keepers": {
      "n": 5,
-      "spread": 59.9,
-      "focus": 70,
-      "gain": 10.1,
-      "noise": 0.5
+      "spread": 60,
+      "focus": 69.8,
+      "gain": 9.8,
+      "noise": 2.7
    },
    "cleaner": {
      "n": 6,
-      "spread": 57.8,
-      "focus": 71,
-      "gain": 13.2,
-      "noise": 6.8
+      "spread": 59.4,
+      "focus": 70.1,
+      "gain": 10.7,
+      "noise": 1.4
    },
    "cleaner_marksman": {
      "n": 5,
-      "spread": 51.2,
-      "focus": 62.1,
-      "gain": 10.9,
-      "noise": 0.7
+      "spread": 51.8,
+      "focus": 61.9,
+      "gain": 10.1,
+      "noise": 0.5
    },
    "revenant": {
      "n": 3,
-      "spread": 63.1,
-      "focus": 73.3,
-      "gain": 10.2,
-      "noise": 1.6
+      "spread": 61.9,
+      "focus": 75.4,
+      "gain": 13.5,
+      "noise": 2.2
    },
    "duplicate": {
      "n": 5,
-      "spread": 58.4,
-      "focus": 69.3,
-      "gain": 10.9,
-      "noise": 3.2
+      "spread": 60.5,
+      "focus": 69.7,
+      "gain": 9.2,
+      "noise": 2.4
    },
    "barghest": {
      "n": 3,
-      "spread": 26.2,
-      "focus": 36.8,
-      "gain": 10.5,
-      "noise": 2.2
+      "spread": 24.8,
+      "focus": 36.5,
+      "gain": 11.8,
+      "noise": 3.5
    },
    "kelpie": {
      "n": 3,
-      "spread": 54.6,
-      "focus": 67.3,
-      "gain": 12.8,
-      "noise": 1.8
+      "spread": 52,
+      "focus": 67.1,
+      "gain": 15.1,
+      "noise": 2.8
    },
    "redcap": {
      "n": 3,
-      "spread": 31.4,
-      "focus": 44,
-      "gain": 12.6,
-      "noise": 2
+      "spread": 31.1,
+      "focus": 41.9,
+      "gain": 10.9,
+      "noise": 1.8
    },
    "boggart": {
      "n": 2,
@@ -87,18 +87,18 @@
    },
    "churchgrim": {
      "n": 3,
-      "spread": 42.1,
-      "focus": 54.7,
-      "gain": 12.6,
-      "noise": 3.4
+      "spread": 43.7,
+      "focus": 55.7,
+      "gain": 12,
+      "noise": 2.1
    },
    "supporter": {
      "n": 2,
-      "pinned": 3.8
+      "pinned": 4
    },
    "hollow_man": {
      "n": 6,
-      "pinned": 92.4
+      "pinned": 91.8
    },
    "the_tenant": {
      "n": 2,
@@ -106,57 +106,57 @@
    },
    "the_choir": {
      "n": 6,
-      "pinned": 99.1
+      "pinned": 99.4
    },
    "precedent": {
      "n": 3,
-      "spread": 59.2,
-      "focus": 71.1,
-      "gain": 11.9,
+      "spread": 61,
+      "focus": 72.2,
+      "gain": 11.2,
      "noise": 0.7
    },
    "carrion_file": {
      "n": 4,
-      "spread": 45.8,
-      "focus": 58.4,
-      "gain": 12.7,
-      "noise": 3.6
+      "spread": 45.2,
+      "focus": 57.3,
+      "gain": 12.1,
+      "noise": 1.3
    },
    "the_understudy": {
      "n": 5,
-      "spread": 60.2,
-      "focus": 71.8,
-      "gain": 11.7,
-      "noise": 0.8
+      "spread": 61.5,
+      "focus": 73,
+      "gain": 11.5,
+      "noise": 6.3
    },
    "surveyor": {
      "n": 2,
-      "spread": 27.5,
-      "focus": 34.5,
-      "gain": 7,
-      "noise": 3.7
+      "spread": 28.8,
+      "focus": 34.4,
+      "gain": 5.6,
+      "noise": 1.9
    },
    "quarantine_unit": {
      "n": 2,
-      "pinned": 0.1
+      "pinned": 0.2
    },
    "cuckoo_array": {
      "n": 2,
-      "spread": 58.3,
+      "spread": 58.6,
      "focus": 66.2,
-      "gain": 7.9,
-      "noise": 2.1
+      "gain": 7.7,
+      "noise": 3.8
    },
    "long_walker": {
      "n": 2,
-      "pinned": 0.6
+      "pinned": 0.1
    },
    "auditor": {
      "n": 4,
-      "spread": 52,
-      "focus": 64.5,
-      "gain": 12.5,
-      "noise": 1.6
+      "spread": 49.4,
+      "focus": 62.3,
+      "gain": 12.9,
+      "noise": 2.5
    },
    "washer_ford": {
      "n": 2,
@@ -167,37 +167,37 @@
      "pinned": 100
    },
    "grindylow": {
-      "n": 3,
-      "spread": 70.6,
-      "focus": 80.1,
-      "gain": 9.4,
-      "noise": 2.9
+      "n": 4,
+      "spread": 30.5,
+      "focus": 42.1,
+      "gain": 11.6,
+      "noise": 1.5
    },
    "knockers": {
-      "n": 2,
-      "pinned": 100
+      "n": 6,
+      "pinned": 99.7
    },
    "spriggan": {
      "n": 3,
-      "spread": 38.9,
-      "focus": 55.5,
-      "gain": 16.6,
-      "noise": 3.4
+      "spread": 42.5,
+      "focus": 55.4,
+      "gain": 12.9,
+      "noise": 5.7
    },
    "nuckelavee": {
      "n": 2,
-      "pinned": 8.5
+      "pinned": 8.2
    },
    "hedley_kow": {
      "n": 6,
-      "pinned": 97.6
+      "pinned": 97.8
    },
    "apple_man": {
      "n": 2,
-      "spread": 36.8,
-      "focus": 42.5,
-      "gain": 5.7,
-      "noise": 7.2
+      "spread": 36.6,
+      "focus": 42.1,
+      "gain": 5.5,
+      "noise": 0.8
    },
    "the_committee": {
      "n": 2,
@@ -205,24 +205,24 @@
    },
    "night_registry": {
      "n": 4,
-      "spread": 62.1,
-      "focus": 76.2,
-      "gain": 14,
+      "spread": 63.1,
+      "focus": 73.9,
+      "gain": 10.7,
      "noise": 2.5
    },
    "the_locum": {
      "n": 5,
-      "spread": 49.3,
-      "focus": 61.5,
-      "gain": 12.2,
-      "noise": 2.4
+      "spread": 49.2,
+      "focus": 63.1,
+      "gain": 13.9,
+      "noise": 1.9
    },
    "lost_property": {
      "n": 2,
-      "spread": 54.9,
-      "focus": 64.1,
-      "gain": 9.2,
-      "noise": 2.1
+      "spread": 54.3,
+      "focus": 63.2,
+      "gain": 8.9,
+      "noise": 1.3
    },
    "the_minutes": {
      "n": 2,
@@ -230,71 +230,74 @@
    },
    "waiting_room": {
      "n": 3,
-      "spread": 63.2,
-      "focus": 71.8,
-      "gain": 8.6,
-      "noise": 2.1
+      "spread": 63.4,
+      "focus": 70.8,
+      "gain": 7.4,
+      "noise": 0.3
    },
    "the_predecessor": {
      "n": 4,
-      "spread": 55.5,
-      "focus": 69.2,
-      "gain": 13.7,
-      "noise": 6.7
+      "spread": 58.6,
+      "focus": 71,
+      "gain": 12.5,
+      "noise": 5.1
    },
    "switchboard": {
      "n": 6,
-      "pinned": 86.1
+      "pinned": 86.9
    },
    "the_census": {
      "n": 3,
      "spread": 64.3,
-      "focus": 75.3,
-      "gain": 11,
-      "noise": 4.2
+      "focus": 76.5,
+      "gain": 12.1,
+      "noise": 1
    },
    "the_courier": {
      "n": 2,
-      "spread": 17.5,
-      "focus": 25.2,
-      "gain": 7.7,
-      "noise": 4
+      "spread": 17.8,
+      "focus": 25,
+      "gain": 7.2,
+      "noise": 1.8
    },
    "the_relay": {
      "n": 2,
-      "spread": 52.6,
-      "focus": 58,
-      "gain": 5.4,
-      "noise": 6.7
+      "spread": 52.7,
+      "focus": 58.9,
+      "gain": 6.2,
+      "noise": 2.8
    },
    "the_stanchion": {
      "n": 2,
-      "pinned": 4
+      "pinned": 5.8
    },
    "the_yield": {
      "n": 2,
-      "spread": 48.7,
-      "focus": 62,
-      "gain": 13.3,
-      "noise": 3.8
+      "spread": 46.8,
+      "focus": 57.8,
+      "gain": 11,
+      "noise": 1.5
    },
    "the_overwriter": {
      "n": 3,
-      "spread": 62.6,
-      "focus": 71.7,
-      "gain": 9.2,
-      "noise": 3.9
+      "spread": 64.1,
+      "focus": 72.7,
+      "gain": 8.6,
+      "noise": 1.9
    },
    "the_arrears": {
      "n": 2,
-      "pinned": 14.3
+      "spread": 14.7,
+      "focus": 21,
+      "gain": 6.3,
+      "noise": 1.5
    },
    "the_margin": {
      "n": 5,
-      "spread": 46.7,
-      "focus": 59.6,
-      "gain": 12.8,
-      "noise": 6.2
+      "spread": 45.3,
+      "focus": 59.3,
+      "gain": 14.1,
+      "noise": 2.3
    }
  }
 }
@@ -25,7 +25,7 @@ import { readFileSync } from "node:fs";
 import path from "node:path";
 import { NPCS } from "./content.mjs";
 import { ROSTER } from "./roster.mjs";
-import { runFight } from "./simulate.mjs";
+import { runFight, makeRng } from "./simulate.mjs";

 const ROOT = path.resolve(path.dirname(new URL(import.meta.url).pathname.replace(/^\/([A-Za-z]:)/, "$1")), "..");
 const base  = JSON.parse(readFileSync(path.join(ROOT, "tools", "lethality-baseline.json"), "utf8"));
@@ -59,8 +59,9 @@ const rec = focus.creatures[KEY];
   defect this file exists to help find. Solo also matches what check-lethality records. */
 const N = Number(opt("--count", 0)) || (rec?.gain !== undefined ? rec.n : 1);

-/* The same generator shape the guards use, so a seed here names the same fight there. */
-const mk = seed => { let s = seed >>> 0; return () => ((s = (1664525 * s + 1013904223) >>> 0) / 4294967296); };
+/* THE generator the guards use, not merely one of the same shape. A seed here names the
+   first fight of `simulate.mjs --seed <n>` exactly. */
+const mk = makeRng;
 const firstName = c => (c.name ?? "?").split(" ")[0];
 const hp = c => `${Math.max(0, c.hp)}/${c.hpMax}`;

@@ -116,7 +117,7 @@ for (const mode of MODES) {
                                              : "  —  party picking targets at random";
  console.log(`\n${"=".repeat(78)}\n${N} × ${spec.name.toUpperCase()}${how}\n${"=".repeat(78)}`);
  console.log(lines.join("\n"));
-  console.log(`\n  → ${r.won ? "PARTY WINS" : r.wiped ? "PARTY WIPED" : "neither side finished it"}`
+  console.log(`\n  → [${N > 1 ? mode : "solo"}] ${r.won ? "PARTY WINS" : r.wiped ? "PARTY WIPED" : "neither side finished it"}`
    + ` in ${r.rounds} rounds · ${r.partyDown} of ${party.length} down · ${r.dead} dead`);
 }

@@ -98,7 +98,11 @@ export function seedFor(base, key = "") {
 }

 /** mulberry32 — small, fast, and seedable, which is the only property that matters. */
-function makeRng(seed) {
+/* R-265. Exported because anything that cites a measured fight has to draw from the same
+   stream to name the same fight. tools/playthrough.mjs had its own LCG, so "seed 2" meant
+   one fight there and a different one here, which quietly broke the only thing that tool
+   exists for. */
+export function makeRng(seed) {
  let a = seed >>> 0;
  return () => {
    a = (a + 0x6D2B79F5) >>> 0;