When a grade rests on proof, the capital backing a job does not have to cover the worst case of a judge being wrong — only the narrow case of a proof being contested. That is why coverage on this network can be priced in basis points rather than percentages, and why a challenge is a bonded claim against a specific verdict rather than an appeal to a committee.
Judges themselves put down a deposit and lose it if their call is overturned. If a judge never answers, the deadline decides on its own — no job waits on a silent grader. The challenge mechanics are covered under three positions.