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Evaluating Double Deck Games - A New Idea

There are a lot of money-making opportunities for the individual card-counting Blackjack player in double-deck (DD) games, but there are also a lot of bad DD games out there, so before you waste your time and $$$, let’s discuss the differences.

Casinos and their average patron know that the fewer decks used, the better it is for the player, which is why the 6 to 5 single-deck game of BJ can succeed, at least among “average” players. But you and I are not average, so we avoid those lousy single-deck games, but can we avoid a lousy DD game as well? Unfortunately, it’s not as simple as just looking for a 3 to 2 payoff on a “blackjack” because all the DD games I know of do indeed pay the correct amount for a natural – at least they’re not messing with that for the moment.

Many casinos do, however, alter the DD game in such a way as to negate its advantages, yet still treat it as what I call a “premium” game. Such games typically have a higher minimum bet, are few in number and are usually watched very closely by the casino supervisors as though somebody may get rich by playing them. A good example is the DD game that Harrah’s here in St. Louis offered as of Nov., 2011. First of all, there are only 3 tables (of a total 26) that offer DD games and the rules on them actually give the casino an edge “off the top” that’s higher than the edge they have in their 6-deck games! Plus, the minimum bet is $25 with a $2500 maximum, as opposed to the $5-$1000 for the six-deckers and then they deal out just a smidgen over half the cards. For all intents and purposes, the game is unbeatable in the long run by most card counters. Even a team cannot beat those games because they have the “nms” – no mid-shoe entry – rule there.

I have always preached that a counter must be able to realize a long-term advantage of at least one percent in order to make the effort worthwhile; otherwise, you might get stuck early on and spend the rest of your life trying to dig out. And that 1% really is the minimum, which leads us to a discussion of what’s called N0 (the letter N and the number 0). The logic here is that it’s possible to calculate how many hands you must play in order to overcome a one Standard Deviation downswing, given a specific overall playing advantage. For the math geeks, the formula is N0 = Var/EV^2, with VAR being variance and EV being expected value, but you don’t need to know that in order to find a good DD game. However, you do need to take N0 into consideration, especially if you’re a part time counter, so let me explain. Whatever number of hands N0 is, it’s the number of hands you could play – and play perfectly – but still show no profit, just due to bad “luck” alone. The bigger your overall advantage, the lower N0 will be; that is, you’ll have to play fewer hands to overcome the 1 SD loss due to bad luck. For the calculation of N0 for a game, go to: http://www.bjmath.com/bjmath/refer/N0.htm You’ll need a copy of Don Schlesinger’s book “Blackjack Attack” to make it work, but I’ll cover some representative games here.

One of the better DD games in Las Vegas is available at Bellagio; that’s no secret. The dealer stands on soft 17, you may double on any first two cards, including after splitting pairs but surrender is not available, although penetration is pretty good; about 62 cards of 104 are used before the shuffle. The casino has an edge of 0.19% over the Basic Strategy player, but here too, it’s treated as a premium game. There are only 8 tables, the minimum bet is $50 and the games are watched closely. Nonetheless, it’s still pretty good and yields a long-term edge of about 1.2% when using a $50-$400 bet spread.

If you were to play the Bellagio DD game while faithfully adhering to a $50-$400 bet spread and playing through all counts, positive and negative – something you typically have to do in DD games – the N0 works out to be 19,144 hands. If you were to play 60 hands per hour, you could play for over 319 hours; a full month of 10 hour days and still not show a profit, simply because of variance (or “bad luck”, if you prefer.) And that’s at one of the best DD games out there!

Now let’s look at a more typical DD game where the dealer hits soft 17, you may double on any first two cards, but not after splitting pairs and penetration is 52 cards of 104. The casino’s edge is 0.53%, which is not better than many six-deck games, but let’s play it anyway. With a 1-8 bet spread, a long-term edge of about 0.60% is attainable; well below my recommended 1%, but I want to make make a point here. The N0 for this game is a whopping 86,501 hands. This means you could play 60 hands per hour for 1441 hours – 6 months of eight hour days – and still be just even due to luck alone. Yes, in both of these examples you could also get lucky to the upside and actually make a profit, but since when do we, the card counters of the world, depend upon luck?

So what kind of DD game is worth our trouble if we’re a part time counter who can play, say, 300 hours a year or about 18,000 hands? What we really need is a game that has a N0 of fewer than 18,000. At least that way our year of play will not have been spent in vain; we have a fighting chance to overcome a one SD move to the downside. Remember, in the long run you’ll win if you have an edge – it’s just when will you collect the $$$ that’s the issue here. In my series "Beating the DD Game", the absolute minimums I espouse are a game where the dealer hits soft 17; you may double on any first two cards and double after splitting pairs. This gives the casino an edge of 0.40%. Penetration is the key here: with 52 cards of 104 used, this game yields a long-term edge of only about 0.71% if a 1-8 bet spread is used, so it’s on my “do not play” list.

However, if you can find such a game with 62 of 104 cards used before the shuffle, it just makes my minimum; a 1-8 bet spread yields a 1.02% long-term advantage. As we expect, the N0 drops to 27,552 but it’s not the 18,000 we’d like. If the penetration is 70 of 104, the N0 is 18,464 – at last, the Promised Land. Of course we got there because the overall edge is now in the 1.25% area, which demonstrates how important penetration is in DD games, especially if you don’t play them very often.

The lesson here is to not play DD games just because it seems like they’re worthwhile due to using fewer decks. The “premium” game some casinos are dealing simply aren’t worth your valuable time and $$$ - stick with the 6-deckers if your local DD isn’t dealt beyond the 50% point. If you’re in a situation where the penetration is better than that, then it’s probably worth a shot because it only takes a few extra cards to turn an “okay” DD game into a “great” DD game. Hey, bribe the dealers with generous tips; it works for me.

I'll see you here next time.

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