This will probably be a real spam magnet but anyhow….
Some time ago, while I was still at uni, with a few friend I tried card counting blackjack. Like all casino games blackjack is in the house’s favour. However over the course of a deck (or several decks) this is not always the case for every hand. By keeping track of the cards that have come out of the deck, you can determine when the game is in your favour and increase your bet accordingly. Contrary to popular opinion you don’t need to track the actual cards that have been removed but rather keep a running tally on their effect on the game.
Certain cards are good for the player. A deck rich in aces gives more chance of blackjack with its higher pay out and a deck rich in tens gives the dealer who must hit automatically until he gets 17 or more, a much higher chance of going bust. Conversely a deck rich in 4, 5 and 6’s is bad for the player. The dealer will more rarely go bust as these cards will save him from going bust when he gets to totals of 14-16. The basics of such a system of counting and betting were first shown by Edward O. Thorpe and rely on both inferring a proportional measure of the expectation for a single bet and the use of the Kelly Criteria, in essence betting amounts proportional to your expected chance of winning.
In a small deck this is particularly effective as you get towards the end of the cards, but it’s also effective in large decks as well. Particularly if they place the cut card, which determines the point when the decks are reshuffled, near the end. Casinos of course take a dim view of the idea that someone else other than the house could be playing a positive expectation game and so try to stop it typically by banning the players in question. Counting is not illegal, but the casino is free to exclude anyone they don’t like.
The reality of the situation though is that unless you have a large bank roll you are better off working at McDonald’s, and if you are playing alone its pretty easy to detect someone with wild swings in their betting patterns, particularly if they are winning money. Still it was possible for us on many trips to the casino to sit off a table not playing until the deck was “hot” and then jump in and lay some bets. This makes you pretty obvious but if you are serious low rollers like we were when we were uni students then I doubt they are worried particularly.
Successful counters these days work in teams. A reasonably interesting book on the subject is Bringing Down the House, which although it concentrates too much on the glamour of the high-roller lifestyle and not enough on the actual scheme.
As for our little project, it slowly disappeared into nothing more than an occasional drunken trip to the casino where we would attempt to count through the haze. I note though now that the Star City Casino has put in continuous shuffle machines and the whole hope of counting is gone. I wonder whether it is actually a positive revenue deal for them. After all people like me will only play if they have the knowledge that they might just be able to have an edge even though in practice they rarely will. For the casino I guess giving this money away is worth it if it means avoiding serious counters.