Hitting soft 17 is good for the casino

7 February 2016

By John Grochowski

QUESTION: Why are there differences between when the blackjack dealer must hit on soft 17 versus stay on soft 17? I know you'd have to be more aggressive when it's hit on soft 17, but I'm not sure about the logic for those three plays that are different. Why hit on soft 19 against a dealer 6, double on soft 18 against a dealer 2, and hit with 11 against a dealer ace?

ANSWER: Probabilities are different for the final dealer hand when he hits soft 17 vs. those when he stands. When the dealer hits soft 17, he has chances to improve the hand to 18, 19, 20 or 21. He also has chances to bust with a multi-card hit, while the dealer never busts if he starts with soft 17 and stands.

Let’s take your three hands, one by one. We’ll assume a six-deck game in which blackjacks pay 3:2 and you can double on any first two cards, and evaluate it.

Player has 11, dealer shows an ace: Basic strategy calls for hitting if the dealer stands on all 17s, but doubling down if the dealer hits soft 17. On the stand on 17 game, the dealer who starts with an ace busts 16.99% of the time, but busts 20.13% when hitting soft 17. That’s enough to reverse strategy on a close-call. On the hit soft 17 game, our average return is $1.12 per $1 wagered when we double, and only $1.10 when we hit. On the stand on 17 game, it’s $1.15 when we hit, and $1.12 when we double.

Player has soft 18, dealer shows a 2: Basic strategy says to stand if the dealer stands on soft 17, and double if the dealer hits soft 17. This is an extreme close call. The average return per $1 wagered on a stand on 17 game is $1.23 if you stand, and $1.21 if you double. On a hit soft 17 game, it’s $1.12 if you double and $1.11 if you hit. The gap isn’t as wide on bust percentages this time, at 35.67% on hit soft 17 games vs. 35.35% on standing games, but when we’re looking at a hand that’s nearly a toss-up at the start, that gap is enough to reverse course.

Player has soft 19, dealer has 6: Basic strategy says to stand on soft 19 against all dealer up cards on standing games, but shows a double-down opportunity if the dealer hits soft 17. Again, that opportunity arises because the dealer busts more often in the hitting game. Bust percentages with a 6 up are 43.93% if the dealer hits soft 17, 42.28% if he stands.

On all of those hands, the dealer’s average no-busting hand will be a little better if he hits soft 17 than if he stands. But the bust increases are enough for us to be more aggressive about doubling down.


QUESTION: Do slot machines at the ends of rows have higher paybacks?

ANSWER: This may have been true 30 years ago, but putting higher-paying machines at the ends of rows is not common in modern casinos. The theory was that the frequent noise of coins clattering into trays would attract players to a row, and they’d fill the other seats. Coins don’t drop into trays anymore, and while machines go into celebration mode for big wins, there’s no obvious sign that machines are paying off frequently. The incentive to place machines at the ends of rows is gone.

Slot directors on my source list have told me they generally have games of the same type and denomination configured for the same payback percentage.