The advantages of basic strategy in Blackjack kick in when the player has an opportunity to increase his bet, by doubling down or splitting. It is as important as Bingo to know the double-down situations in which the player has the advantage, because this is the chief method by which players reduce the house advantage.

Three basic rules govern this play for hard hands:

- Double down when the player’s cards total 11 and the dealer shows a Ten or less.

- Double down when the player’s cards total nine and the dealer shows a Four, Fire or Six.

- Double down when the player’s cards total 10 and the dealer show a Nine or less.

For soft hands, three rules also are essential:

- Players double down with a soft 13 and soft 14 when the dealer shows a Five or Six.

- Players double down with a soft 15 and soft 16 when the dealer shows a Four, Five or Six.

- Players double down with a soft 17 and soft 18 when the dealer shows a Three to Six.

Any other situation should be handled by the rules for standing and hitting.