Kelly Criterion Bankroll Simulator
Bet optimally over 20 rounds to maximize your bankroll. A Jane Street / SIG final-round classic.
Kelly Formula (even odds)
f* = 2p − 1
You start with $1,000. A biased coin is shown — it lands Heads with probability p (randomly chosen between 52% and 70%).
Each round, you choose how much to bet. Win = +bet, Lose = −bet. Play 20 rounds.
After the game, compare your bankroll to the Kelly-optimal strategy using the same coin flips.
The Kelly fraction for even-odds bets is f* = 2p − 1. This maximizes the long-run growth rate.