Closed form for multicandidate first-to-ahead-by-k voting (generalized gambler’s ruin)
Derive a closed-form expression for the winning probability in the first-to-ahead-by-k voting process when multiple candidates race simultaneously with dependent counts (the multinomial generalization of gambler’s ruin), rather than restricting analysis to a two-candidate approximation.
References
This process is a generalization of the classic gambler's ruin problem , but with simultaneous dependent races between all pairs of candidates . Since there is no known closed form for this general case, the analysis is simplified by assuming the worst case, i.e., that a correct candidate with probability $p$ races against a single alternative with probability $1 - p$.
— Solving a Million-Step LLM Task with Zero Errors
(2511.09030 - Meyerson et al., 12 Nov 2025) in Section 3.2 (First-to-ahead-by-k Voting and Scaling Laws)