The Right to Stop a Balanced Deck Is Worth $2.62
Turning all fifty-two cards lands on exactly zero, which makes zero the floor rather than the value. Backward induction over the grid of remaining cards gives the exact rational 41984711742427/15997372030584, and a two-line argument shows the optimal policy can never finish below zero in any deal. The article carries the small-deck ladder, the stopping boundary the table actually produces, and two plausible rules that lose money against it.