This is probably the shortest strategy I'll ever write: only Double on Spread 7 or better. Period. That's it. End of strategy.

Okay, if you're still reading I'm assuming it's because you want a little detail. It's still pretty simple, but here it is: the player only gets an edge when the spread is 7 or more. This is actually quite obvious. At Spread 7, 7 cards will give you a winning hand. And since there are 13 cards from Deuce to Ace (2 ,3 ,4 ,5 ,6 ,7 ,8, 9, 10, J, Q, K, A), that means that only 6 cards will cause you to lose.

Spread 7 gives the player about a 54% chance of winning and it gets better from there on up to around 85% at Spread 11. So the strategy is to only Double on the Spreads that give you an edge, namely 7 through 11. Spreads below 7 give the house an increasingly stiff edge and should be avoided.

If the first two cards dealt to you or the dealer are an Ace and a ten-count card (10, Jack, Queen or King), that is "blackjack". If you have blackjack, you win automatically, unless the dealer also has blackjack, in which case it is a push (tie). Blackjack pays higher than an ordinary win, which pays even money. Blackjack pays 3 to 2, meaning you win 3 dollars for every 2 you bet. Blackjack is sometimes called "a natural".

After you receive your first two cards, you may have the option to "double down". This means you can double your original bet. Most casino only allow you to double down when the value of the first 2 cards is 9, 10 or 11. If you double down, the dealer will give you only one more card and then draw the cards needed to complete his own hand.

When your first two cards have the same value (for example, a pair of sevens), you have the option to "split". To split, you have to place another bet equal to your original bet. Then the two cards are split and you play them as separate hands. Some casinos allow you to "resplit" if you get another same-value card.

Special blackjack rules apply when you choose to split Aces. When you split Aces, you only receive one more card on each hand and if you get 21, it is not considered blackjack.

Insurance

When the dealer's face-up card is an Ace, some casinos will ask if you want "insurance". The cost of insurance is half your original bet. Your insurance bet pays 2 to 1 if the dealer gets blackjack, which will equal the amount you lose on the original bet. For example, say your original bet was $10. The dealer has an Ace showing and you decide to place an insurance bet for $5. If the dealer gets blackjack, you lose your original $10 bet but win $10 on the insurance bet so you are even. If the dealer does not have blackjack you lose your $5 insurance bet and play the hand by normal blackjack rules.

Casinos deal blackjack from a single deck or from multiple decks. It's traditional for the dealer to "burn" or discard the top card after shuffling.

Blackjack rules may vary from casino to casino. Here are a few rules variations you may encounter:

• Dealer stands on soft 17.
• Player may double down on any first two cards.
• Player may double down on any number of cards.
• Player may double down on split pairs.
• Player may "surrender" his hand after the first two cards and lose half his bet.