How to win at blackjack

Blackjack is the one casino game where how you play changes the odds. Played on hunches, the dealer wins a few chips in every hundred bet. Played by basic strategy, the best play for every hand worked out by computer long ago, the dealer's edge comes down to about half a percent: close to an even game. This guide takes you through the reasons behind the main rules of basic strategy, then gives the full charts for the rules played on openseat (six packs, the dealer standing on soft 17, doubling after a split, no surrender).

Think of the hole card as a ten

Sixteen of the 52 cards in a pack count ten (the tens, jacks, queens and kings), almost a third. So the most likely card under the dealer's up card, and the most likely next card for anyone, is a ten. Read the dealer's up card as up card plus ten: a 7 showing is probably a 17, and a 6 showing is probably a 16, which has to draw again and may well go bust.

That one idea explains most of the charts below.

Stand on a stiff hand against a weak dealer

A hard 12 to 16 is a stiff hand: one more card can easily take it over, and as a total it beats nothing but a bust. What to do with it depends on the dealer:

• Against a 2 to 6, stand (on 12, only against a 4 to 6). The dealer shows a weak card and has to draw on a stiff total too, and goes bust about four times in ten with a 5 or 6 showing. Let the dealer take the risk.
• Against a 7 to ace, hit. The dealer probably has 17 or more already, and your 15 loses to it. Hitting a 16 against a 10 is grim, but standing on it is worse.

Double down when the dealer is weak, and the next card is likely to help

Doubling puts twice the chips on a hand at the moment it is most likely to win. The classic doubles:

• Hard 11: double against everything but an ace. Any ten makes 21.
• Hard 10: double against a 2 to 9.
• Hard 9: double against a 3 to 6.
• Soft 13 to 18: double against the dealer's weakest cards (see the soft chart). An ace and a 7 against a 6 should be doubled, not stood on.

Never double when the dealer shows a ten or an ace on a 10 or less: the dealer is too likely to have a strong hand.

Always split aces and eights; never split tens or fives

• Aces: split. Two hands that each start on 11 beat one soft 12.
• Eights: split. A pair of eights is 16, the worst total in the game; two hands starting on 8 are far better, even against a ten.
• Tens: never split. Twenty is a winning hand already. Splitting it throws away a likely win for two hands that are only good.
• Fives: never split. A pair of fives is a 10: double it instead.
• Nines split against everything but a 7, a 10 or an ace; twos, threes and sevens against a 2 to 7; sixes against a 2 to 6; fours only against a 5 or 6.

Never stand on a soft 17

An ace and a six looks like a 17, but a soft hand cannot go bust on one card, so taking one costs nothing. And 17 is a weak total: it wins only if the dealer busts. Hit it, or double it against a 3 to 6. Soft 18 is trickier: stand against a 2, 7 or 8, double against a 3 to 6, and hit against a 9, a 10 or an ace.

Turn insurance down

Insurance pays 2 to 1 when the hole card is a ten, so it would break even if a ten came up one time in three. It comes up less often than that: with an ace showing in a fresh six-pack shoe, 96 of the 311 cards left are tens, about 31 percent. Over time, insurance loses around 7 percent of what you put on it. That includes "even money" on a blackjack, which is insurance by another name. Skip it every time.

Bet sizes: no system beats the dealer

No pattern of bets changes the odds of a single hand. The best known system, doubling after every loss (the Martingale), runs into the table's limits quickly: from a bet of 10, six losses in a row take you to 640, more than the 500 limit, and six in a row happens more often than it feels like it should. Since the shoe is shuffled before every hand, counting cards does not help either. Bet what you are happy to lose on one hand, and let basic strategy do the work.

Racing friends to the most chips

At a friend's table the aim is not to win chips but to end with more than everyone else, which changes how you bet:

• Ahead, bet small. Every hand is a slight loss on average; a lead is kept by not risking it. If the player behind you bets big, matching their bet keeps you level whatever the cards do.
• Behind with few hands left, bet big. Small bets cannot close a gap of a few hundred chips in three hands. A large bet gives you a real chance, and second place counts for nothing anyway.
• Mind the bottom. Under 10 chips and you are out, so near the end of your stack a bet that leaves you something is worth more than it looks.

Your hands are still played by the charts: the betting is where the race is won.

The basic strategy charts

The play for every hand, for these rules. The dealer's up card runs across the top (A is an ace). H hit, S stand, D double (hit if you may not), Ds double (stand if you may not), P split.

Hard totals

Soft totals

Pairs

You do not have to learn it all at once. Playing alone on openseat, turn on the hint and the table shows the chart's play for each hand as it comes. After a few dozen hands the main lines stick.

Ready? Play blackjack, or go back to the rules.