Current Five

Two of your own, five shared

You get two cards face up. Five more appear in the middle, in three stages, and both you and the host build the best five out of the seven available.

When you act

Once, before the middle is complete: fold and lose the opening, or continue by adding a second stake. After that the remaining cards appear and the round settles itself.

The host's threshold

The host qualifies with a pair or better. If not, the opening pays and the continuation is returned.

Acting on incomplete information

You commit before the last two shared cards appear. Everything about the margin here comes from that: the host sees the finished board, you did not.

2.16 percent, if played properly

Continue with any pair, any ace, or two cards that both connect with the board. Fold the rest. Played that way the game returns about 97.8 percent; played loosely, several points less.

Why cards are different

A grid draws afresh every round. A deck does not: every card that has already appeared changes what is left, so the odds move while the hand is in progress. That is the only family here where what you have seen tells you something.

Order of play is the whole game

In most card games the house acts last and knows more when it acts. The rules that look arbitrary — draw to sixteen, fold below a threshold, act before the fifth card — are all attempts to price that asymmetry.

Where the margin lives

A well-played card game has one of the narrowest margins anywhere: a fraction of a percent. Played carelessly, the same game can cost ten times that. The gap between the two numbers is the value of knowing the rule.

A caution about systems

Doubling after a loss does not change any game's margin. It changes the shape of the loss — many small wins and one very large loss — and the total expected result stays exactly where it was.