Quote from NoDoji:
Blackjack is a game in which you can truly have an edge. I'm a consistent winner at blackjack, not because I count cards (although I must say having an exceptional visual memory is helpful), but because I can play the game strictly by the rules with no emotional disruption, and with very defined rules for managing risk, booking profits and sizing up.
These are games that aren't simply a pull of a handle, toss of a coin. Once you bring the human factor into play, there's room for an edge to be exploited by more than just the casino.
I'm pretty sure that Blackjack and Poker are the two casino games that people play professionally on a consistent basis because of this.
This is for the folks who still think discipline can't provide an edge in blackjack:
http://www.elitetrader.com/vb/showthread.php?threadid=221709
Jim Wortman, a former Atlantic City casino executive and nationally recognized gaming expert, said it was entirely plausible for one player to win so big at the blackjack tables - if he had sound knowledge of the game, deep pockets and exercised self-discipline.
"There are a lot of people who have the knowledge and who have the bankroll, but they fall short of discipline and start changing to losing hands," said Wortman, gaming director at the Conrad N. Hilton College of Hotel and Restaurant Management at the University of Houston.