The St. Petersburg Paradox
A coin-flipping game whose average winnings are infinite. How much of your own money would you actually pay to play?
1713 (posed by Nicolaus Bernoulli), 1738 (published by Daniel Bernoulli)19 min read
Swiss mathematics
Gabriel Cramer
1704 – 1752
Geneva mathematician remembered for Cramer's rule for solving linear systems. In a 1728 letter to Nicolaus Bernoulli he proposed two responses to the St Petersburg wager that are still the standard ones: value money by its square root rather than its amount, or cap value above some threshold entirely. Both ideas predate Daniel Bernoulli's published paper.