The Cost of One More Hand

Why "just one more" is the most expensive phrase in gambling.

You're up $200. You've had a good session. You're thinking about leaving. But then you think: "Just one more hand. What's the harm?"

The harm is that "just one more" is how you lose everything.

Here's the math: if you're playing blackjack with a 1% house edge and you bet $100, the expected value of that hand is -$1. You expect to lose $1. But that's just the expected value. The actual result could be a win or a loss.

If you lose, you're down $100. If you win, you're up $100. But over time, the -$1 expected value adds up. Play 100 more hands and you expect to lose $100.

But "just one more hand" never stays at one more hand. It becomes two more hands. Then five more hands. Then you've lost all your winnings and you're chasing losses.

The best strategy is to set a time limit or a win limit. When you hit that limit, you leave. No matter what. No "just one more." Because "just one more" is how the casino wins.