Blackjack

Blackjack is the best bet on a casino floor, and the reason is that your decisions actually change the outcome. In roulette or slots the edge is fixed; in blackjack it depends on how you play.

The game

Both you and the dealer aim to get closer to 21 than the other without going over. Cards count at face value, face cards are 10, and an ace is 1 or 11, whichever helps.

A blackjack is an ace plus any ten-value card on the first two cards. It should pay 3:2.

The dealer has no choices: they must draw to 16 and stand on 17. That fixed behaviour is what makes the game solvable. You always know exactly what the dealer will do.

Your options

• Hit: take another card
• Stand: keep your total
• Double down: double your bet for exactly one more card
• Split: separate a pair into two hands
• Surrender: forfeit half your stake and fold, where offered
• Insurance: a side bet against a dealer ace, and almost always a mistake

Why the edge is so low

Basic strategy is the mathematically optimal decision for every possible hand against every dealer upcard. It has been computed exhaustively, it is not disputed, and it fits on a card.

Play it correctly under good rules and the house edge is about 0.5%. Play by instinct and it is closer to 2%: four times as expensive for the same game.

This gap is the whole point. Blackjack is not a low-edge game; it is a game that can be played at a low edge by people who learned the chart.

The rule that ruins it

6:5 blackjack. Paying 6:5 instead of 3:2 on a natural adds about 1.39% to the house edge, roughly quadrupling it.

These tables are now common, usually at lower minimums. The difference is not marginal. A 6:5 table is a worse bet than most video poker and comparable to a decent slot. Check the felt before sitting down; it is printed there.

Side bets

Perfect Pairs, 21+3, Lucky Ladies and the rest carry house edges between 2% and 15%. They exist to recover the margin the main game gives up. None of them is worth playing.