GENERIC BASIC STRATEGY
THE HIGH-LOW SYSTEM
HOW TO WIN WITHOUT GETTING KICKED OUT
If you find a double-exposure game with rules so good that you will change your trip plans to play double exposure instead of whatever game you originally intended to play it probably will be a game in which naturals pay 3:2. In that situation, the high-low counting system will do the job. Therefore, this chapter presents double-exposure decision numbers for the high-low count. This is the same counting system used in for single-exposure blackjack.
Table 17 provides the decision numbers from -1 to +6 for use when the dealer is pat or potentially pat. Table 18 is the same range of numbers for use when the dealer is stiff or potentially stiff and hits soft seventeen. Table 19 is the same as 17 except the dealer stands on soft seventeen. All the calculations in tables 17-19 are based on six decks and no doubling down after splitting.
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Blackjack Combinatorial Analyzer analyzes the many variations of double exposure, and was the tool used to develop the decision numbers in this website.
For decision purposes you need a count per deck. The method for finding it is the same as was discussed in High-Low System chapter. Start with zero after a shuffle. Keep a running count, counting all cards you have seen since the shuffle. Divide this running count by the number of decks you have not seen to get the count per deck. You should stand, hit, or double down only if your count per deck (not rounded) is equal to or greater than the number in the table.
Each count per deck is worth about 0.8% at double exposure.
This is in contrast to the 0.5% per count per deck at single-exposure blackjack. Your advantage at double exposure is more volatile than your advantage at single exposure -at higher counts your advantage is much higher. Therefore, for equivalent bet sizes you can make more money at double exposure than at single exposure.
Insurance at double exposure is the same as is explained in High-Low System chapter, and the decision numbers of table 3 are applicable to double exposure too.
Note that you might want to double down on a natural against fourteen, fifteen, or sixteen if the count is high enough. This is true only if naturals pay only even money. Do not double down on a natural if it pays 3:2.
Suppose you have 4-4 and have a choice of doubling down, splitting, or hitting. Doubling down on your total of eight is more profitable than splitting 4-4 if the dealer has six or less or soft seventeen or less, regardless of the dealer's action on soft seventeen. If the dealer has hard twelve to sixteen, then basic strategy says splitting 4-4 is more profitable than doubling down on eight. When the count per deck gets above the numbers shown in table 17, then doubling on eight is more profitable than splitting 4-4.
With 6-6 against seventeen, split if the count per deck is less than +2 and hit if the count per deck is +2 or more.
With 3-3 and 2-2, splitting is always more profitable than doubling down.
The numbers for soft twenty against twelve and thirteen are stand/double. If the count per deck is equal to or greater than the number in the table, then double down.
The numbers for soft eighteen against twelve through sixteen are hit/stand if you cannot double. For example, if you have soft eighteen and the dealer shows thirteen, double if you can. If you cannot double, then hit if the count per deck is less than zero or stand if the count per deck is zero or more.
The numbers for soft eighteen against dealer A-A through A-5 are for when to double.
When the dealer stands on soft seventeen, you have soft eighteen, and the dealer shows A-A through. A-5, ifyou do not double it does not matter whether you hit or stand. So take a card on a negative count, and stand on a positive count.
With 7-7, if you do not split then either hit or stand according to the decision number for fourteen. Likewise with 6-6: If you do not split, then play according to the decision number for twelve.
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