Why and When to Surrender in Blackjack

6 October 1997

By Alan Krigman

Basic strategy for blackjack is full of fiats providing prudent players cause for pause. Bettors often wonder whether it's really right to split eights against a 10. Or hit 12 against a two. Or double on soft 18 against a four. But, misgivings aside, most blackjack buffs follow these and other enigmatic edicts faithfully because they're what "the book says" to do.

Except for surrender - an option offered in enlightened casinos to sacrifice half a bet without playing the hand. In "late surrender," the usual form, the option is void and the whole bet lost if the dealer has a blackjack.

Surrender isn't mentioned in every book or printed on every strategy card. Only the good ones. And players aplenty forego this tactic on hands for which it's recommended. But more than a few exercise the option when alternate plays would be superior.

Here's the why and when.

By deliberately forfeiting half your wager, you lose fifty cents on the dollar. Based on the chances associated with cards available to you and the dealer, certain blackjack hands have expected values below fifty cents on the dollar. You reduce your theoretical loss by surrendering these, and only these, hands. In six-deck games where the dealer stands on soft 17, the eight combinations in the accompanying table meet this criterion. On the average, these situations will occur about once every 26 hands.

Entries in the table show the benefit of surrendering over hitting - the next most favorable choice in each case. Savings are the theoretical amounts recovered for every $100 bet; net advantage gain is the corresponding percentage reduction in house edge, accounting for the likelihood that each hand will occur as well as the savings. Here's an example of how to interpret the table. Surrendering 10-6 versus a dealer's 10 yields theoretical savings of $3.47 per $100 bet and trims house edge on the hand by 0.046 percent. Overall, surrendering under the indicated circumstances cuts house edge in the game by 0.069 percent.

Rules for surrender depend on specific playing conditions. For instance, in eight-deck games where the dealer stands on soft 17, surrender 8-7 versus 10-up along with the hands in the table. Likewise, in one-deck games where the dealer hits soft 17, no hands are surrendered against nine; instead, surrender 7-7, 10?5, 9-6, 10-6, and 9?7 versus 10 or ace, and 10?7 versus ace.

Oh yes. A warning to solid citizens who didn't read "the book" carefully or who play hunches, and meekly surrender when the laws of probability call for more assertive action. These bettors may feel vindicated by the next cards to appear. Those truly vindicated are the casino bosses who implemented surrender in the first place. Incorrect surrenders more than repay what casinos lose to bettors who properly exploit the option.

Here are some typical errors and their consequences. Surrendering 8-8 versus an ace has a penalty over splitting the pair of $11.46 per $100 bet. Surrendering rather than splitting 8-8 versus nine, 10, or ace gives the house 0.021 percent greater edge than need be. And naively surrendering all two-card totals of 15 versus nine- or ace-up is worth 0.019 percent in edge to the casino.

The bettors' bard, Sumner A Ingmark, advocated adhering to the axioms of arithmetic when he articulated:

Knowing what's proper and doing it,
Rather than blithely eschewing it,
Guards against losing and ruing it.