The league schedule generator tells an organiser which teams have clinched a play-off place and which are out. A wrong "clinched" is the kind of mistake a club notices at the worst moment, so this run checked it the blunt way.
eval/fuzz-race.mjs builds random part-played leagues (3 to 7 teams, up to 8 fixtures left, two points systems, point adjustments, any number of spots). It plays out every win, draw and loss for the remaining fixtures, up to 6,561 outcomes a league, and records each team's best and worst finishing rank. It compares those with playoffRace. It also checks that the fast bounds route, used when too many fixtures remain to enumerate, never claims more than the exact one, and that the Monte Carlo odds give 100% to clinched teams, 0% to eliminated ones and add up to the number of spots.
Result over three seeds of 300 leagues (about 4,400 team rows): no disagreement. The check is pinned in the test suite. It covers points ties only; the race counts a tie against the team by design, so goal-difference tie-breaks are not tested here.