D266 - A round's cost depends on which position it grows, by a factor of twenty

decided · 2026-08-25 · read off the first run of the new binary

D264 established that a shape has two costs and they rank differently. The first real run of orbistoun-suggest shows the same effect across positions, and larger:

position grown	candidates swept in one round
learned	214,798,320
verb	4,158,806,400
tail	5,059,730,000

A round re-sweeps every pattern using the grown position, so cost tracks how widely that position appears. learned is in four patterns; tail is in nearly all of them. Growing tail by one word is twenty-three times the work of growing learned by one.

That inverts the ordering the slot list was written with. It asks the shortest list first, on the reasoning that one word changes the most where there are fewest - which is true about coverage and exactly wrong about cost. Nothing is changed here yet, because the cheap position is also the least valuable one and the trade has not been measured; recorded so the next person to tune the loop starts from the numbers rather than from the comment.