Between the years1950 and 1960 a book about blackjack was published and showed how using mathematical probabilities you could increase your odds to the point where they were better then the casino. One such book even became a best seller. Once this knowledge became well known the popularity of blackjack skyrocketed making it the number one table game, and it still is today.
The casinos enjoyed the new found popularity because it brought in allot of money, but did not like the fact that more and more people were winning money. They tried to change the rules of blackjack to put the odds back in there favor, but all that did was anger the regular blackjack players to the point where they stopped coming to gamble. This hurt the casinos to the point where they eventually had to revert back to the old blackjack rules.
The casinos did eventually find a way to put the odds back in there favor. By adding several decks of cards in play at any one time, shuffling machines and random shuffling it made the odds to difficult for all but a few players to calculate. One thing they never really mentioned was the fact that the books on how to increase your odds and beat the house were very difficult to understand without having a Degree in mathematics.