In the previous series on advanced blackjack playing strategies I explained how to use card counting to vary your bets and gain the edge over the casino. In essence you bet more when the count tells you have the advantage and bet less when the count indicates the dealer has the better of it.
Besides using card counting to vary the size of your bets, you can also use it to vary the basic playing strategy. When you think about it, it makes sense. If your count tells you that the remaining unplayed card are rich in ten value cards, then hitting a hard 16 when the dealer shows a 10 face card might not be the best play in this situation. Likewise, taking insurance when the dealer shows an ace upcard might also make sense in this situation (since you are betting that the dealer has a ten in the hole).
Blackjack computer software can be used to determine the value of the true count that a player should deviate from the basic playing strategy. These values, called indices, have been published in a host of blackjack books including my Blackjack: Take The Money & Run.
When I first started playing blackjack seriously some 25 years ago, I would spend weeks memorizing tables of indices. For every hand and dealer upcard an index was listed. For example for the popular Hi/Lo card counting system, the index number for hard 12 vs. 2 was +3. Normally the basic strategy play is to hit a hard 12 if the dealer shows a 2 upcard. But the index number of +3 tells you that when your true count is +4 or higher you should deviate from basic strategy and stand. The reason of course is that with a true count of +4, the unplayed cards are rich in tens and if you drew a card you would have a high probability of busting. There are no guarantees you will win if you stand but you will win more money in the long run if you stand when the true count is +4 or higher (likewise you should hit if it’s +3 or less).
Memorizing 50 or so of these strategy indices was no fun. Worst I was making a lot of mistakes while I was playing because I would forget the right index number. Then some thing wonderful happened that changed everything. Don Schlesinger (author of Blackjack Attack) published an article in Blackjack Forum in which he calculated that it was not necessary to learn 50 or so indices. In fact, you’ll realize about 90% of the potential gain by just learning a handful of plays.
The table at the end of this article summarizes the true count index for these plays (Hi/Lo count). You should use the basic strategy play for all other decisions. Here are some examples of how to use the information in the table.
Suppose you are dealt a 7,4, the dealer shows an ace, and your true count is +4. The dealer will first ask if you want to take insurance and you would since your true count is above the insurance index number where taking insurance is profitable in the long run. In the unlikely event the dealer doesn’t have the ten in the hole, you would have to play out your hand. The basic strategy play for hard 11 against a dealer ace upcard is to stand. However, the index for this play is +2 (see table) which means you should double down if your true count is greater than +2.
If you still find the task of learning 16 indices to daunting, then I’d recommend you try learning this simplified version which groups the strategy changes by true count. I’ve simplified things a bit by combining some plays under the same true count number. The error in doing this is very small and you’ll still be benefiting from most of the gain.
True Count +1 (or more)
Stand on 16 against a 10
Double on 11 vs. ace
Double an 9 vs. 2
Stand on 12 vs. 4
True Count +3 (or more)
Stand on 12 vs. 3
Stand on 12 vs. 4
Double on 9 vs. 7
True Count +5 (or more)
Stand on 15 vs. 10
Split 10’s vs. 5
Split 10’s vs. 6
Double on 10 vs. 10
Double on 10 vs. ace
Stand on 16 vs. 9
True Count -1 (or less)
Hit 12 vs. 6
Hit 13 vs. 2
True count -2 (or less)
Sit out hands or bet as small as possible or leave the table.
Here are some examples of how to use the above information. Suppose you are dealt a 9,3 (12) and the dealer shows a 6 with a true count of -1. In this case you would vary your basic strategy and hit rather than stand. Likewise if you are dealt a 6,4 (10) against a 10 and your true count is +5 you should double down.
As a general rule strategy changes are more valuable (important) in single deck games compared to multiple deck games. It’s possible, in fact, to get the edge in single deck games by just flat betting and varying your basic strategy based upon the count (although I recommend you also vary your bets in single deck games as well).
Learning to vary your playing strategy as well as your bet size according to the count will make you one hell of a tough blackjack player. Over time will win much more money than lose. Trust me on this.
Basic Strategy Deviations
Play Index Strategy
16 vs. 10 0 Stand at +1 or higher
15 vs. 10 +4 Stand at +5 or higher
10,10 vs. 5 +5 Split at +6 or higher
10,10 vs. 6 +4 Split at +5 or higher
10 vs. 10 +4 Double at +5 or higher
12 vs. 3 +2 Stand at +3 or higher
12 vs. 2 +3 Stand at +4 or higher
11 vs. ace +1 Double at +2 or higher
9 vs. 2 +1 Double at +2 or higher
10 vs. ace +4 Double at +5 or higher
9 vs. 7 +3 Double at +4 or higher
16 vs. 9 +5 Stand at +6 or higher
13 vs. 2 -1 Stand at 0 or higher
12 vs. 4 0 Stand at +1 or higher
12 vs. 6 -1 Stand at 0 or higher
Take insurance when:
True count is 3 or higher (2.5 or higher in double deck games and 1.5 or higher in single deck games)