You will notice that when a house-edge is discussed in blackjack, it is with the disclaimer that the edge requires perfect strategy. Well, that perfect strategy is the ‘basic’ blackjack strategy based on points totals. With the right knowledge and the right situation, there is a chance to adjust your strategy for the individual cards which make up that points total. This is known as ‘composition dependent strategy’ and can lower the house edge a little further if used correctly. This article outlines how composition dependent strategy works and when you might want to use it.
First of all, you’ll find some examples of when composition of the hand might affect your decision making. After that a look at the situation in which you can use these plays – which are actually very rare nowadays. Finally the debate about whether it is worth learning this strategy at all, with the much bigger edges available from learning even simple card-counting methodology often considered to the better choice after you get the basic strategy memorized.
Here is the ‘classic’ example of a composition dependent strategy. You have a total of 12 against a low dealer card like a 5. Ordinarily, you would choose to ‘stand’ here. Since there is a high chance of the dealer going bust, the risk of hitting a 10 yourself before the dealer has a chance to play is considered too big.
However, a 12 can be completed in several ways. The ‘composition’ of your 12 can be any of the following 2-card combinations:
2 +10, 3 +9, 4 +8, 5 +7 or 6 +6.
One of those combinations, the 2+10, removes one of your ‘danger cards’ from the deck – making it less likely that you will bust by hitting your 12 on this occasion. The other combinations actually take away many of the small cards which might help the dealer (6, 5, 4, 3 and 2 all give him a hand which will beat your 12 if you stand).
The difference here is minuscule, and relies on you being in a rare Single Deck Blackjack game even make any difference at all. However it does demonstrate how the individual cards which compose your hand can influence your decision making.
There are certain situations where you can deviate from the basic points strategy with a 16 made up of 3 cards, in situations where you would hit on a 16 made up of 2-cards. Hoping for the dealer to bust, even when he is showing a 10 as his up-card is considered to be an ever-so slightly ‘least bad’ option compared to hitting here.
Again the situation needs to be perfect to make this work. There should be only one deck in the game to start – and the game should not have any ‘negative rule variations’ which might kill the very advantage you were looking for by changing your strategy to suit the composition.
Card counters keep track of the ratio of small cards to big ones which have been dealt, and then increase their bets when the count becomes favorable. There are many card counting systems like the Hi Opt 2 System and Revere Hi-Lo Count.
If you look at the example with the 12 from the perspective of a card counter, it is easy to see how composition strategy falls behind. Here you are changing up your play based on seeing a single 10. Imagine in that same game that you had kept track of the last 5 hands and seen a total of 10 more small cards than you would have expected by chance compared to the high cards you have seen. Instead of getting a few thousandth of a percent advantage based on the single 10, you have now pushed the whole game into positive territory thanks to your knowledge that the deck has proportionally more 10’s than it normally would (which is positive for the player).
This is just one example. In a multi-deck game, composition strategy is more or less redundant, with the difference being so infinitely small it is hardly worth the mental effort to memorize the changes. If you instead find ways in which the count for the entire deck can change your strategy, the opportunity will arise to make potentially statistically significant changes in the game probabilities.
There is certainly a place for composition dependent strategy in blackjack. That place is in single deck games as an add on to card counting strategy and compositional strategies which come from this should be based on the overall count as well as the specific cards in your hand.