Count of balanced non-terminating starting deals
Determine the total number of balanced non-terminating starting deals—starting configurations with 26 cards in each player's hand—that lead to periodic cycles of play in Beggar-My-Neighbor with a standard 52-card deck under the 1911 Encyclopaedia Britannica rules.
References
Although the original open problem is now resolved, several questions remain open. Second, how many balanced non-terminating games exist?
                — A Non-Terminating Game of Beggar-My-Neighbor
                
                (2403.13855 - Casella et al., 19 Mar 2024) in Conclusion