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>
