[Math] Expected value for blackjack

gamblingprobabilityprobability theory

In the game of blackjack, the odds of winning each hand are slightly less than 50 percent. As you play an infinite amount of hands, you would always lose money because you would win less than 50 percent of the time. By this rationale, wouldn't your highest odds of winning be if you only played one game?

Best Answer

Definitely. Consider going to the casino with $100\$$. Your best strategy would be to bet the $100 \$ $ immediately in a single hand.

Betting a lesser amount each time does not change the odds of winning a single hand, but it does lower the variation of your return. In other words, the probability that you end up in the plus gets lower the more bets you make.

NB: The above is assuming you bet the same amount multiple times, e.g. betting $100\$$ is a better strategy than betting $10$ times $10\$$, which is a better strategy than betting $100$ times $1\$$. But there are other strategies, for instance this one, that uses Martingales.

And ofcourse the best strategy is to bet $0\$$ and go buy a sandwich across the street.