Dice Question Streamline Icon: https://streamlinehq.com

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.

Information Square Streamline Icon: https://streamlinehq.com

Background

The paper presents a constructive method that yields a balanced non-terminating game and identifies 30 starting deals that reach the same 62-trick cycle. Achieving balance required careful backward play to select pieces that shift many cards to the second player during reconstruction.

Earlier searches often produced unbalanced non-terminating configurations, highlighting the rarity of balanced non-terminating games. The authors' success opens the question of how many such balanced infinite games exist across all possible starting deals.

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