[RogelioKWhite]

In a 52-card deck there are 16 ten-valued cards: four tens, four jacks, four queens, and four kings. (For purposes of simplification, when I refer to a card as a "ten" or "X," it is understood to mean any 10, Jack, Queen or King.) Every other denomination has only four cards, one of each suit. You are four times more likely to pull a ten out of the deck than, say, a deuce. Because of this, when the blackjack dealer’s upcard is "high" —7,8,9,X, or A—he has a greater likelihood of finishing with a strong total than when his upcard is "low" - 2,3,4,5, or 6.
Thus, if the dealer’s upcard is a 7, 8, 9, X, or A, and you are holding a "stiff" - any blackjack hand totaling 12 through 16 - you want to hit. When the dealer’s hand indicates strength, you do not want to stand with a weak hand. Even though, when you hit a stiff, you are more likely to bust than to make a pat hand, you must give your hand a better chance of beating the dealer’s by taking a hit. You will lose more money in the long run if you stand on these weak hands when the dealer shows strength.
On the other hand, if the dealer’s up card is 2, 3, 4, 5 or 6, and you are holding a stiff hand, you should stand. Since the dealer must hit his stiff hands, and since stiffs bust more often, hitting your weak hand is not advantageous.
Similarly, if the dealer’s up card indicates he may be stiff, it is more advantageous to double down or to split pairs, thereby getting more money onto the table when the dealer has a higher chance of busting. You double down and split pairs less often when the dealer shows a strong upcard.
This is the basic logic of blackjack basic strategy. There are exceptions to these oversimplified guidelines, as the actual basic strategy decision for any given hand is determined by working out all of the mathematical probabilities.
The Generic Blackjack Basic Strategy provided below will get you almost all of the value available to players from Basic Strategy in most games. If you only want to learn one chart, this is the one you should learn.
At the end of this article you will find a Comprehensive Blackjack Basic Strategy, which shows every basic strategy variation for all traditional blackjack games—single deck, multi-deck, games with special rules, etc. Most of the differences in these charts have very little dollar value to players, and a number of high stakes pros simply ignore them. But if you enjoy memorizing charts, or if you play single deck exclusively, for example, you may want to learn the specific basic strategy for that game and gain those few extra hundredths of a percent. The main value of the Comprehensive Blackjack Basic Strategy card comes from any unusual rule, such as Early Surrender, with a high value to the player in and of itself.