Blackjack and Roulette have one thing in common. Both casino games have had numerous systems developed to beat the game. Only Blackjack has seen a system that delivered the results that players wanted to see. Counting cards and playing aggressively when the shoe is in favor of the player can beat blackjack. No system that wins like this has been found for roulette. This only adds to the mystic of Blackjack and its popularity with players both online and in live casinos.
Blackjack can be beaten since the card counting system will indicate when the odds are in favor of the players. When this is the case, the strategies can be taken to extremes since the chances of hitting hands and making great double downs is improved beyond what can normally be expected. Another factor is the player must be comfortable with the strategy and be able to use it with complete accuracy. This is not possible for all players.
Casinos and card counters are in a constant battle and the casinos have used many measures to defend against card counting like early shuffles, short cut placement on six-deck shoes and keeping track of player betting patterns if they seem to be winning more than a hot streak would seem to give to the players.
Some systems try to keep track of all of the cards, while other systems are just interested the high card count versus the total cards left in the shoe. The system you choose depends on the way you can handle the system you choose. Comfort level and being able to do it when in a game is the critical detail that will tell the tale. If it works for you that is the one to stick with over time. Confidence in the way you play and count is important to winning in the long run.