Frequent blackjack questions

31 July 2014

By John Grochowski

Every game has its own list of most frequently asked questions, the things readers ask most often. And the table game that draws the most reader e-mail is blackjack, with some questions popping up over and over.

So let’s do a little blackjack FAQ, with a few of the things you ask most.

• Are fewer decks always best for the player?

If all other rules are equal, the house edge is lower if fewer decks are used. However, the other rules are not always equal.

Let’s say you encounter a single-deck game where the dealer hits soft 17, you’re allowed to double down only on two-card totals of 10 or 11, you can split pairs only once with no resplits, and you may not double down after splitting pairs. That’s a host of negative rules, and brings the house edge against a basic strategy player to 0.44 percent.

Now let’s say the same casino offers a six-deck game where the dealer stands on all 17s, you resplit pairs up to three times for a total of four hands and you can double down on any first two cards, including after splits. The house edge is 0.40 percent, lower than in the single-deck game.

One of my local haunts used to offer that six deck game and also permit late surrender, dropping its edge to 0.33 percent.

You have to weigh all the rules, not just the number of decks. That said, there is one deal breaker. If blackjacks pay only 6-5 instead of 3-2, it increases the house edge by 1.4 percent, more than triple the entire edge of the weakest game detailed above. No matter how many decks are in play, avoid games with 6-5 blackjack payoffs.

• Why are fewer decks better?

With fewer decks, you are more likely to get blackjacks, and more likely to draw 10s on your double downs. That’s because each card removed from play has a greater impact on the remaining deck when fewer decks are used.

Let’s say the first card you’re dealt is an Ace. After all, if we’re to get a blackjack the first card must be either an Ace or a 10. In a single-deck game, 16 of the other 51 cards are 10 values. That means 31.37 percent of the remaining cards will complete the blackjack. If six decks are in play, removing an Ace means 96 of the remaining 311 cards are 10-values. That’s 30.87 percent, meaning you have a lesser chance of completing your blackjack in a six-deck game than in a single-deck game.

Without going into all the arithmetic, your chances of the second card being an Ace when your first is a 10 also are higher with fewer decks, as are your chances of drawing a 10 when your first two cards are in double-down territory.

• Why do you say the house edge is higher if the dealer hits soft 17? If he doesn’t hit, he can’t bust.

Seventeen can’t win against a pat hand of 17 or better. The best it can do is push another 17. A dealer’s 17 beats you only if you bust, or if you stand on 16 or less.

When the dealer hits soft 17, he can turn the hand into 18s or better, and even if he draws a 5 through 9, it doesn’t bust; it just puts him in 12-16 territory for another hit. On balance, the dealer will beat you more often if he risks the occasional bust in exchange for chance to build better hands.

• Is the house edge higher with automatic shufflers?

No, the house edge is the same with most automatic shufflers as on hand-dealt games, and on his Wizard of Odds site, Michael Shackelford says the house edge is slightly lower on games with continuous shufflers, where cards are shuffled back into the deck after every hand.

That doesn’t mean everyone should run out and look for continuous shufflers. Quite the opposite. The positive effect of having all cards available in the shuffler instead of in a discard tray is minute, decreasing the house edge by only 0.02 percent.

The big tradeoff that with no play stoppages for shuffles, there are more hands per hour, and more chances for the house edge to work against you.

Let’s say you’re a basic strategy player betting $10 a hand on a game with a 0.40 percent house edge that drops to 0.38 percent with a continuous shuffler. And let’s say you’re at full table, averaging 50 hands per hour at a hand-shuffled game, 60 with an automatic shuffler with play stoppages to change decks, and 70 with an automatic shuffler.

Per hour, you risk $500 and average $2 in losses at the hand-shuffle game, risk $600 and lose $2.40 with the regular automatic shuffler, and risk $700 and lose $2.66 with the continuous shuffler.

The house edge doesn’t increase with the shuffling machines, but they make a little extra dent in your bankroll nonetheless.


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