In Blackjack, Optimum Play Varies with House Rules

Versions of basic strategy, the rules governing optimum blackjack play, differ slightly among reference sources. This doesn't mean experts disagree on the best decisions for specific circumstances. Or factors beyond well-known laws of probability influence chances of winning with a particular hand against a certain dealer upcard. Or leeway exists for opinion.

Sure, demagogues masquerading to the masses as masters may know not whereof they speak. Their railings may simply be wrong. But, subtle distinctions also pop up among pronouncements of true gurus. They result from variations in how the game can be spread.

One such variation involves the number of decks from which cards are drawn. Most older books - including many classics - were written when blackjack was frequently dealt from single decks instead of six- or eight-deck shoes. Here are a few examples of common confusions. In single-deck blackjack, it's best to "double down" on 11s against dealer aces, and likewise on eights against dealer fives or sixes; in multi-deck games, it's preferable to hit rather than double under these conditions. Similarly, in single-deck games, players optimize potential gains by splitting pairs of sixes and sevens against dealer sevens and eights, respectively; in multi-deck blackjack, these hands would be hit and not split.

Another discrepancy arises because players originally couldn't double down on hands formed by splitting pairs. With this policy, still practiced in a few joints, it's more profitable to hit than split certain pairs. For instance, the probabilities favor hitting a pair of twos against a dealer's two when subsequent doubling is not permitted, and splitting when it is. Analogously, some charts advocate hitting - not splitting - pairs of fours against dealer fives or sixes; these assume players can't double if they then draw fives, sixes, or sevens to either of the fours.

Surrender further illustrates why apparent uncertainties in rules of basic strategy may be illusory. Surrender, the decision to recover half a bet without playing the hand, is offered in enlightened casinos. Since it's not widespread, though, this option is ignored in many otherwise accurate charts and lists. The omission doesn't imply doubt that it's the statistically-correct play in the right situations. The math clearly shows that solid citizens gain over 0.07 percent advantage in six- and eight-deck games by surrendering rather than hitting or standing on 15s against dealer 10s and on 16s against dealer nines, 10s, or aces.

The problem, of course, is how to determine the proper version of basic strategy for any particular game. Single- versus multi-deck and double down after splits are the key parameters.

The surest way is to ask a pit boss for a copy of the basic strategy card issued by the casino. These cards are prepared for the staff and aren't normally given to patrons, but polite requests are rarely rebuffed. Next best is to find books that have first copyrights after about 1985 and don't shout "guaranteed to win" on their covers, then ascertain that they precisely state the options on which indicated rules are based. As a last resort, check a few critical indicators yourself. Charts are for one- or two-deck games if they say double on 11 against a dealer's ace. They assume you can't double after splitting if they tell you to hit rather than split pairs of twos or threes against dealer two or three, and never to split fours. If surrender isn't included in a nominally applicable chart but is available where you play, modify the instructions yourself.

Finally, casino contenders who consider cash conquest as much a question of craft as kismet can pursue the principles espoused by Sumner A Ingmark, the punters' poetical pundit:

Since true gamblers their power from knowledge derive,
If you tire of letting fate skin you alive,
You can spring for a book priced o'er $2.95,
Seeking secrets of play that will help you to thrive.