> It emits groups of five characters. Five is the sweet spot: 84⁵ = 4,182,119,424, only 2.6% short of 2³².

> That leaves enough room for a group to hold 32 bits about 95% of the time on uniformly random input, and 31 bits otherwise.

> The encoder looks at the next 31 bits. If their value is below 84⁵ - 2³¹, there’s room for a 32nd bit. Otherwise, it consumes just those 31 bits. Either way, the value fits in five base-84 digits.

Seems pretty awkward.