Among the common rules variations in blackjack, 6-5 payoffs on two-card 21s is by far the toughest on players. Paying only 6-5 instead of 3-2 on blackjacks costs 1.39 percent, an amount larger than the entire house edge against a basic strategy player at most blackjack tables. Take a run-of-the-mill six-deck game where the dealer stands on all 17s, the player is allowed to double down after splitting pairs and may resplit pairs up to three times for a total of four hands. The house edge is only 0.41 percent.
That one rule, paying 6-5 on blackjacks, is more than triple the house edge than the entire set of rules on a common six-deck game.
A reader asked me to put that in dollars and cents instead of house edges and tenths of a percent, so let’s use a sample of 441 hands — about two hours of head-to-head play, or around eight hours at a full table. At about one blackjack per 21 hands, you’d average about 21 two-card 21s. On one of those, the dealer would also have blackjack and you’d push — we all know not to take even money unless the count is right.
That leaves 20 blackjacks on which you’re paid. Let’s say you’re betting $10 a hand. If you’re only getting $12 payoffs instead of $15, that means the rule has cost you $60. That’s six bets worth in your 441 hands.
The sharp-eyed number crunchers among you might note the $60 shortfall in 441 hands is only a 1.36 percent increase in house edge instead of 1.39. That’s just the effect of rounding the number of blackjacks per hour. But the message is clear: 6-5 blackjack payoffs are much tougher on your bankroll than traditional 3-2 pays.
