In his fascinating history of the topic, Fortune’s Formula, William Poundstone points out that for a favorable bet that pays odds of $A for a bet of $1, the optimal Kelly bet is the percent of your capital equal to your edge, divided by the odds, A. In blackjack, the typical favorable edge was usually between 1 and 5 percent and the odds, or payoff per dollar bet, averaged a little more than 1. So, following the criterion when the card count was good, I bet a percentage of my bankroll that was a little less than my percent advantage. Kelly’s criterion is not limited to two-value payoffs but
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