Playing soft 17 at blackjack

1 February 2014

By Henry Tamburin

The dealer’s play in blackjack is purely mechanical and quite straightforward. They must draw a card if their hand is 16 or lower, and stand on 17 through 21. There is, however, one dealer rule that could differ from one casino to another, and even amongst blackjack tables within the same casino. It’s known as the soft 17 rule; namely, whether the dealer stands or hits on a soft 17.

A soft hand in blackjack is any hand that contains an ace that is counted as an 11. Therefore, an ace-6 is a soft 17. So is ace-3-3 and 2-2-ace-2. Each casino decides whether to allow their dealers to hit soft 17 (known as h17), or stand on soft 17 (s17), and let players know by printing it on the felt layout, and usually on a sign located on the table.

You might think that the soft 17 rule seems trivial. I mean, come on, what’s the big deal if the dealer hits or stands on one lousy hand? Well this might shock you, but it is big deal, and if your local casino hasn’t switched from s17 to h17 yet, it’s only a matter of time before it will.

When a casino changes its rule from s17 to h17, guess who gets the short end of the stick? Of course, it’s the players. The h17 rule increases the house edge by about 0.2 percent (rule dependent). In dollars and cents, it costs a player about two cents for every 10 bucks wagered.

It turns out the dealer will bust about 0.3 percent more often when she hits soft 17, rather than stands (assumes all other rules are equal). So, then, why does the house edge increase by 0.2 percent? Because when she doesn’t bust, the dealer winds up with a total that is greater than 17, which, more often than not, beats the players. The latter more than compensates for the increased bust frequency, resulting in the 0.2 percent increase in house edge.

Here’s the effect that the soft 17 rules has on double- and on six- and eight-deck games, and what strategy changes you should make when the dealer hits soft 17 (instead of stands).

Double-Deck Game

Some casinos in the South have h17 on their double-deck games, while others have s17. The latter is preferred as long as the rules also allow you to double down after pair splitting (das) and the 3-2 blackjack payout. The house edge on an h17/das game is 0.40 percent and for s17/das, it is a very respectable 0.19 percent.

If you must play a double deck h17/das game, you need to make these strategy changes compared to the s17/das game.

1. Double down on 11 against dealer ace (instead of hitting).
2. Double down soft 18 against dealer 2 (instead of hitting).
3. Double down soft 19 against a dealer 6 (instead of standing).

Six-and Eight-Deck Game

Given a choice, you are better off playing a single- or double-deck game. However, if you must play a six-deck game, the best rules are s17, das, and rsa (house edge 0.34 percent). When the casino offers the same game with h17, you need to make the same strategy changes as above for the double-deck, h17 game. (Ditto for the eight-deck game).

Some casinos offer late surrender in their six- and eight-deck games, which is a good rule for players who know the correct surrender strategy. The latter is slightly different depending on whether the rules specify h17 or s17.

For an s17 game, you should surrender hard 15 against 10 and hard 16 against a dealer 9, 10 and ace. If the rules specify h17, you would surrender the same hands along with these: hard 15, 17 and a pair of 8s against a dealer ace.

Unfortunately, the trend is going to h17 games in multi-deck games. However if players stop playing the h17 games, and instead play s17 games, perhaps casino managers will think twice about switching to h17 games.


Henry Tamburin is the editor of Blackjack Insider Newsletter (www.bjinsider.com), To receive his free Casino Gambling Catalog visit www.smartgaming.com.