rtcvb32: Hmmm. Maybe. You can probably successfully card count on a deck of 52, but many casinos employ 4 or 6 decks (
300+ cards). Also their shuffling method usually ends up encouraging what's known as card clumping. Those two things together makes card counting fairly difficult if not impossible to employ. You're better off with a good memory, then see how they shuffle cards in groups and adjusting your memory to assume generally where cards are at. But unless you're really determined or a savant, i wouldn't expect much for results.
There exist many different card counting systems, but the most simplistic ones are actually fairly easy to implement with practice. Basically, you keep a running score in your mind and +1 for each 'bad' card (2-6) that is dealt and -1 for each 'good' card (10-A) that is dealt. When the score in your mind is high, like +10 or better, then you increase your bet size because you have better odds since the remaining deck has a higher proportion of 'good' cards. When the score is very low, like -10 or worse, you stop playing and let some other sucker place bets since the remaining deck has a higher proportion of 'bad' cards. You won't know exactly what is coming or when, but it's all about increasing your odds.
That said, an edge of even 3% is still extremely volatile due to variance, and so to offset runs of bad luck you would need to have a deep bankroll and play many many hands (like, tens of thousands of hands at minimum) in order to ensure you are making full use of your advantage.