Focus fire across all 47, and the same confound one turn later (R-260)

Measured in simulate.mjs. For each creature, the pack size whose spread-fire win rate
lands nearest 50% — a fight at 0% or 100% cannot show an effect, which is why R-259's
first sample was three-quarters useless — then focus versus spread, 2000 fights across
three seeds.

31 of 47 creatures had a pack size that could show anything. Focus fire helped 31 of 31,
by more than that row's own noise 31 of 31 times, mean +12.8 points. Best is 6x The
margin, 40.4% -> 61.1%. The other 16 are unmeasurable rather than unaffected: eleven are
trivial six at a time, five are hopeless in pairs.

R-259's decomposition was confounded, and I wrote it while correcting a confound. It
credited the defence ladder with 4-5 points by comparing dodge <=30% against dodge >=55%
— but the low-dodge samples were PAIRS and the high-dodge ones TRIOS. Held at a fixed
pack size, dodge is worth 1-2 points. Pack size is the driver: 8.0 points for a pair,
14-15 for three or more, then flat. What focus fire buys is that a dead creature stops
attacking and a half-dead one does not attack any less.

Two failures, one cause: comparing groups that differ in more than the thing being
measured. The control is cheap and I did not run it until the third time.

The bestiary advised concentrating fire and gave the ladder as the reason — right advice,
wrong reason. It now gives the reason that survives measurement.

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

docs/BESTIARY.md

@@ -79,15 +79,20 @@ Two things follow:
   party misses twice is one where the creature meets the third shot at full value.
 - **Each landing hit makes the next one easier**, in the same round only. The second
   agent to connect is worth more than the first, and against the heavy dodgers below
-  the third is worth more still. Commit a round’s attacks to one target; spreading
-  them lets every defence reset at full value.
+  the third is worth more still.
 
 **What you cannot do is choose who goes first.** Reaction is re-rolled every round, so
 over a fight every agent takes the opening slot about equally often, and there is no
 rule for holding an action. Arranging the party so its best weapon fires last was
-measured in the simulator over six independent seeds and came to nothing
-distinguishable from noise. The ladder is a reason to commit a round to one target,
-not a reason to choreograph the order.
+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 fight 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 twice as much against three or
+more enemies as against a pair. 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. The
+dodge ladder adds a point or two on top of that.
 
 The ones that take the most stripping:
 

docs/REVIEW_LOG.md

@@ -5536,3 +5536,46 @@ settled it, and the first where the wrong explanation had already shipped to a d
 GM would read. The rule I keep relearning: a measurement taken outside the guarded
 pipeline is a hypothesis, not a result, and it does not go in a document until the
 pipeline agrees.
+
+## R-260 — focus fire, all 47, and the same confound one turn later
+
+Focus fire measured across the whole bestiary in `simulate.mjs`. For each creature, the
+pack size whose spread-fire win rate lands nearest 50% — a fight at 0% or 100% cannot show
+an effect of any size, which is why R-259's first sample was three-quarters useless — then
+focus versus spread at 2000 fights across three seeds.
+
+**31 of 47 creatures had a pack size that could show anything at all.** Of those, focus
+fire helped **31 of 31**, by more than that row's own seed-to-seed noise **31 of 31**
+times. Mean gain **12.8 points** of win rate. Best: 6× The margin, 40.4% → 61.1%, +20.8.
+
+The other 16 cannot be measured rather than being unaffected: eleven are trivial even six
+at a time (the party wins ~100%) and five are hopeless in pairs — the supporter, the
+quarantine unit and the long walker wipe the party at 0% before focus fire gets a vote.
+
+**R-259's decomposition was confounded, and I wrote it while correcting a confound.**
+It said the defence ladder was worth 4–5 of the gain, comparing dodge ≤30% against
+dodge ≥55%. Those two groups were not the same fights: the low-dodge samples were PAIRS
+and the high-dodge ones were TRIOS. Pack size is the real driver.
+
+| enemies | mean gain | | dodge within that size |
+|---|---|---|---|
+| 2 | **8.0** | | ≤40%: 7.4 · >40%: 8.6 |
+| 3 | 14.0 | | ≤40%: 13.3 · >40%: 14.2 |
+| 4 | 13.9 | | ≤40%: 13.0 · >40%: 15.2 |
+| 5 | 14.7 | | ≤40%: 14.7 · >40%: 14.8 |
+| 6 | 15.4 | | ≤40%: 14.4 · >40%: 15.7 |
+
+Held at a fixed pack size, dodge is worth **1–2 points**, not 4–5. The gain nearly doubles
+from a pair to a trio and then flattens. What focus fire actually buys is that a dead
+creature stops attacking and a half-dead one does not attack any less; the ladder is a
+rounding error on top of that.
+
+So R-259 corrected R-258's un-piped measurement and then made R-255's confound error in
+the correction. Two different failures with one cause: comparing groups that differ in
+more than the thing being measured. The control is cheap — hold the other variable fixed
+and look within it — and I did not run it until the third time.
+
+**The page says what is true now.** The bestiary advised concentrating fire and gave the
+ladder as the reason, which was right for the wrong reason. It now gives the reason that
+survives measurement, and states that the effect roughly doubles from two enemies to
+three or more.

system.json

@@ -2,7 +2,7 @@
   "id": "ringbrp",
   "title": "The Custodians",
   "description": "A Basic Roleplaying game of agents who cross the crossing to contain what should not be there — and who come back a little less from here each time.",
-  "version": "1.7.14",
+  "version": "1.7.15",
   "compatibility": {
     "minimum": 13,
     "verified": "14.364"

tools/bestiary.mjs

@@ -173,14 +173,18 @@ md += `\n**V** = Vesh, **C** = Cadence. Everything else is baseline-human anatom
     + `  party misses twice is one where the creature meets the third shot at full value.\n`
     + `- **Each landing hit makes the next one easier**, in the same round only. The second\n`
     + `  agent to connect is worth more than the first, and against the heavy dodgers below\n`
-    + `  the third is worth more still. Commit a round\u2019s attacks to one target; spreading\n`
-    + `  them lets every defence reset at full value.\n\n`
+    + `  the third is worth more still.\n\n`
     + `**What you cannot do is choose who goes first.** Reaction is re-rolled every round, so\n`
     + `over a fight every agent takes the opening slot about equally often, and there is no\n`
     + `rule for holding an action. Arranging the party so its best weapon fires last was\n`
-    + `measured in the simulator over six independent seeds and came to nothing\n`
-    + `distinguishable from noise. The ladder is a reason to commit a round to one target,\n`
-    + `not a reason to choreograph the order.\n\n`
+    + `measured in the simulator and came to nothing distinguishable from noise.\n\n`
+    + `**What you can do is kill them one at a time.** Against a pack, every agent putting\n`
+    + `their attacks into the same creature beats spreading them \u2014 in every fight in this\n`
+    + `book whose outcome was ever in doubt, without exception, and by more than the\n`
+    + `measurement\u2019s own noise each time. It is worth about twice as much against three or\n`
+    + `more enemies as against a pair. Most of that is not the ladder above: a creature that\n`
+    + `is dead stops attacking, and one on half its hit points does not attack any less. The\n`
+    + `dodge ladder adds a point or two on top of that.\n\n`
     + `The ones that take the most stripping:\n\n`
     + hardest.map(x => `- **${esc(x.name)}** — dodge ${x.d}%, ${stripsIn(x.d)} landing hits to strip\n`).join("")
     + `\nIt runs the other way too: agents defend on the same ladder, which is why a second\n`