2025/11/26 by Geoffrey Grimmett, Geoffrey R. Grimmett
Arts and Humanities · Psychology · #Themes in Literature Analysis #Counseling, Therapy, and Family Dynamics #Psychotherapy Techniques and Applications
paper · pdf · doi:10.1080/00029890.2025.2563436
A neat question involving coin flips surfaced on X, and generated an intensive “storm” of “social mathematics.” In a sequence of flips of a fair coin, Alice wins a point at each appearance of two consecutive heads, and Bob wins a point whenever a head is followed immediately by a tail. Who is more likely to win the game? The subsequent discussion illustrated conflicting intuitions, and concluded with the correct answer (it is a close thing). It is explained here why the context of the question is interesting and how it may be answered in a quantitative manner using the probabilistic techniques of reversal, coupling, and renewal.