It really depends on the casino. The rules vary from casino to casino. This will affect the house edge. According to the respected Wizard of Odds web site there are over 3,456 rule variations out there. They even have a calculator to figure the house edge at the casino you are visiting.
So job one will be to determine the EXACT house edge offered. Because without knowing that you are clearly just guessing at any possible advantage you might get from counting cards.
In terms of how many decks are used and how often they shuffle, this will be another factor you will need to investigate. Part of being a good card counter is learning where the best opportunities are.
You may need to be quite patient and visit various casinos to find one that you believe offers reasonable odds. Because if you just walk into a random casino and attempt to start counting without taking anything else into account you will almost certainly lose.
Sadly the odds are very much against you. Card counting is well known and understood by the casinos these days. They will be well aware if they are spreading games that are vulnerable to counters.
The big problem is, according to information I've read, a good counter under ideal conditions will probably have an advantage of less than 3% in the long term, with a lot of variance. So you may have to spend a lot of time, money and effort, with a very slim return.
You'd be better off learning poker; since the casino doesn't care who wins at that, and over time the good players come out ahead with a much better return than 3 or 5%.
