Optimal blackjack play

15 October 2017

By John Grochowski

In my close to 30 years of playing blackjack, it's seemed to me that other players are getting better, with a greater percentage playing basic strategy,

That isn't to say the guesswork players have disappeared. Numbers may be reduced, but some remain, and some of their plays are . . . um . . . not optimal.

Here are a few I spotted while playing this summer. All were under the most common rules among casinos near me: six decks, dealer hits soft 17, double down on any firsst two cards, including after splits, split Aces only once but split any other pair up to three times for a total of four hands.

Hit 8-8 vs. dealer's 7: It's almost a mantra to any basic strategy player: Always split aces and 8s.

The hand that trips up the most players is when the dealer has a 10 up. Some just can't bring themselves to make a second bet against a 10.

Failing to split the 8s vs. a 7 is rare, but it's costly. If you hit, you accept an average loss of 40.8 cents per $1 wagered. If you split, you turn that into an average profit of 31.8 cents of per $1 of the original bet.

The player turned a profitable hand into a loser, with a swing of 72.6 cents per $1 of the original bet. Ouch.

Hit 10-4 vs. dealer's 6: Even players who are a little fuzzy around the edges of basic strategy usually know that the better play against a dealer's 6 is to stand if you have hard 12 through 16.

The play made a weak hand worse. If you stand on 10-4 vs. 6, your average loss is 12.1 cents per $1 wagered. If you hit, that rises to 30.9 cents.

It turned into an odd hand. The player drew a 6 for 20, saw what he had done and apologized to the table, saying he'd read the hand as 17. The dealer then strung out a five-card 21 and beat everyone.

Stand on A-2-4 vs. dealer 7: Soft 17 used to be one of the most misplayed hands. Now most players know never to stand on the hand, and some even know to double down if the dealer shows 3, 4, 5 or 6.

Standing on A-2-4 vs. 7 brings an average loss of 10 cents per dollar wagered, while hitting turns that into a 50 cents per dollar profit.


Double down on 7-5 vs. dealer 6: You want to double down when your hand plus a one-card hit will win more than 50% of decisions against a given dealer up card. That's hard to accomplish when a one-card hit will bust you more than 30% of the time, as any 10 value will do here.

Your average loss of 11.9 cents when standing zooms to 34.6 cents per $1 of the original bet if you double down.

A basic: Do not double down with hard totals of 12 or higher.

Double down with 5-4 vs. dealer 7: In the six-deck games I was playing, there are four dealer up cards that make doubling on 9 the best play: 3, 4, 5 or 6.

When the dealer has 7 or higher, the chances of a dealer bust are diminished and the value of doubling down plummets.

With 5-4 vs. a 7, hitting brings an average profit of 17.6 cents per dollar wagered. If you double, that drops to 11.8 cents per dollar of your original wager.

Your average profit decreases as you risk increases. And that is not optimal.

Look for John Grochowski on Facebook (http://tinyurl.com/7lzdt44) and Twitter (@GrochowskiJ).