Full Send vs the Blitz Slider

Why does the max loss jump around? (4v1 = 2, 5v1 = 1, 6v1 = 2)

Not randomness — these are exact probabilities, and the wobble is a real Balanced Blitz mechanic. After sharpening the win odds, the algorithm lines every outcome up from best to worst and deletes the worst outcomes one by one until exactly 10 percentage points of probability have been removed (the same happens at the lucky end). Wherever that deletion stops mid-outcome, the outcome keeps only the part above the 10% line — and that leftover sliver is your max loss.

For 4v1 the outcomes worse than "lose 1" (the defeat plus "lose 2") hold 10.5% between them: the deletion swallows the defeat whole (that is exactly why 4v1 is a guaranteed win) and stops just inside "lose 2", leaving it a 0.5% sliver. For 5v1 that same tail holds only 9.0% — under the line, so the whole tail is deleted and the max drops to 1. For 6v1 a bigger committed force widens the outcome range and the tail grows back to 10.7%, so a 0.7% sliver of "lose 2" pokes out again.

So no, it is not "14.3% minus 10%": the deletion covers an area of the worst outcomes, and what survives is only the part of the last outcome sticking out above the line. A final step then boosts likely outcomes at the expense of unlikely ones, which squashes those 0.5–0.7% slivers down to the 0.02–0.03% you would see in the calculator. The max loss column is exact, but some worst cases are one-in-thousands events.

Related tools: the Blitz 100% chart for the minimum stack against any defender up to 300, and the Blitz Calculator for the full outcome distribution of any battle.