Though Blackjack originated in France, it has been one of the most popular table games in America for decades. Originally played as "21", the game was never as popular in the early American clubs and gambling houses as was poker or craps.

To increase interest in the game, some of the card rooms began to offer higher payouts for certain hands of cards; players who received an ace of spades with a jack of clubs or a jack of spades received a 10:1 bonus.

Thereafter the game of 21 became known as Blackjack because of those two cards. The game of Blackjack remained more or less unchanged until the 1960's when mathematician Edward Thorpe proved that the house edge could be virtually eliminated.

With the help of computers, Thorpe and his colleagues calculated the most advantageous way to play every possible card combination. Based on this research, a set of moves known as basic strategy was developed, and then modified by experts over the years.

Basic strategy led casinos to develop countermeasures to control losses, and today you will find slight variations in Blackjack rules depending on the casino you are in.