Introduction to Basic Strategy
Once you have mastered the basic rules of Blackjack it is time to contemplate learning basic strategy. You will know that depending on the fall of the cards, that players really have very few choices to make. They are whether to stand, hit, double or split. On top of these are casino dependent rules which might call for decisions on whether to surrender or take insurance and also whether the dealer peeks at the hole card or not to see if there is a blackjack. Think of basic strategy as a set of rules for the player which tells him what the optimum decision is in every possible scenario.
How is that possible?
Think of a deck of cards which consists of 52 cards with 4 of each type of card with one in each suit. Given a randomly shuffled deck it is easy to calculate that the probability of any type of card being dealt is 4/52 or 7.6923%.
Now there are 51 cards left in the deck and 4 of each type except the type which has been dealt first. If the first card was an ace then the probability of another ace being dealt is now 3/51 or 5.882% and the probability of any other card is 4/51 or 7.8431% and so on and so forth. Hopefully you can see that it is possible to know the probability of any card being dealt exactly if we know what has already been dealt.
So in a situation where its you against the dealer with one hand, you have 2 cards visible and the dealer has 1 card visible and one in the hole (card face down). it is possible to calculate the probabilities of every possible hole card and then calculate the probabilities of every possible outcome for every player decision that is possible. It is therefore possible to work out which decision gives the player the best chance.
Of course you would never be able to work it out in your head and so its much better and faster to have a computer do it, and so that is what has happened. Computer calculations can produce a chart which shows you the best possible decision in any 1 player versus the dealer with 1 hand situation.
Basic Strategy does not take into account other players at the table or playing more than one hand (although it would be possible to do the calculations) but it is still a very effective guide which optimizes your play.
The basic strategy chart for each set of rules will be slightly different because the probabilities will change with the number of decks and the rules but regardless of the rules most of the basic strategy chart is exactly the same and there is even a universal basic strategy chart which is based on a notional infinite deck. If you are interested in getting really involved in the probability calculations, there are some really great sites which do nothing but. You can find the details on our recommended sites page.
Also take a look at the history of basic strategy and you will get a feel for how it was done precomputer, yes really, some people started working this stuff out manually.