Every day, players come up with new ways to beat blackjack and tweak their play. Some advanced methods of beating the house are illegal; others are not. The legality of advantage play also varies from jurisdiction to jurisdiction, but it is usually legal to beat the game in ways that do not utilize outside devices or otherwise breaking the stated rules of the game. Whether multiple players working together count as “outside devices” has been an enduring point of contention in lawsuits against blackjack teams. Regardless, most casinos are considered private property, so pit bosses and managers can bar you from the premises if they catch you counting or generally attempting to game the system.
Most professional players start off by learning basic strategy in and out. Basic strategy isn’t considered an advantage system or cheating, but it is the foundation for every advantage strategy. Once basic has been mastered, professionals then often practice Hi-Lo, a card counting methodology, for a few months in a controlled setting. After they have solid grounding in both, they start learning basic strategy play variations for Hi-Lo. After a player can do Hi-Lo, basic, and play variations in his sleep, he pulls together a bankroll and plays in a live setting. Some are fine with just Hi-Lo, but others choose to learn more advanced counting strategies or come up with their own. It is important for professionals to know how to play individually, but some people choose to work in teams in order to either insulate themselves from individual risk of ruin or to increase the camouflage of their play so that they can have longer professional careers without being caught.
There are numerous strategies that have been devised to track cards in blackjack. The general idea is to mentally track the balance between cards that are advantageous and disadvantageous to you. The most common system is Hi-Lo, which is a balanced card-counting system. There are other more advanced systems, like Hi-Opt II, but they require greater mental dexterity, concentration, and time to learn. The general idea in any card-counting system is to bet as little as possible when you are at a disadvantage and bet as much as you can safely get away with when the cards are in your favor.
The most common form of advantage play is Hi-Lo card counting. In Hi-Lo, Kings, Queens, 10s, Jacks, and Aces are assigned a value of -1. Cards 2, 3, 4, 5, and 6 are assigned a value of +1. The neutral cards, 7, 8, and 9, have a value of 0. Using simple addition and subtraction, players determine the running count by adding and subtracting chunks of cards as they come out. If there are multiple decks, one divides the running count by the number of decks left in order to determine the true count. The true count, or TC, is the number of player-advantageous cards left in the un-dealt pile per deck. When the TC is higher, card counters bet more; when it is lower, they bet as little as possible.
Other advanced counting strategies like Hi-Opt II with Ace sequencing are much more difficult than Hi-Lo, but they are somewhat more effective. Some players choose to use different systems for different types of games and amounts of decks. For instance, for a longer game with six decks, a counter may use Hi-Lo while specifically tracking Aces. The same player may use Hi-Opt II with Ace and neutral tracking for a single- or double-deck game in order to get a higher degree of playing efficiency (essentially the effectiveness of one’s actions at different counts). In order to utilize a system’s increased playing efficiency, pros memorize deviations from basic strategy when the TC is at different levels. Tracking traditionally untracked cards in a system can further increase playing efficiency.
There are additional advanced playing strategies, but some are no longer used as widely. For instance, it used to be common for teams of players or individuals to peek at the dealer’s hole card in order to dramatically improve their playing decisions. In order to combat this, most casinos now use mirrors that are integrated into the tables so that only the dealers can see. Some casinos even use microchips inside their cards so that a machine can let the dealer know whether or not there is a blackjack without anyone actually seeing the card. The reason some places use electronic card readers is that some advanced players are very good at reading body language and can study dealers for days or weeks at a time in order to determine their tells, much like poker players figure out when somebody is bluffing.
Shuffle tracking is another advanced strategy that is no longer practiced as frequently. Not only is shuffle tracking an extremely difficult skill to master, it can also be derailed by something as simple as another player sitting down. Some players and teams of players are able to track one or more individual cards or clumps of cards in order to manipulate a shoe or deck’s composition during play. If a player knows exactly when one or more cards will come out, and in what sequence, he can play accordingly and bet a large amount when the time comes. In order to combat this, casinos take measures such as using automatic shuffling machines, burning cards between hands, cutting off big sections of the shoe, and using more advanced shuffling strategies. Still, for those blackjack masters who can actually pull it off in live games, the advantages can be very substantial.
There are specialty systems for individual side bets and even specific games that can only be found at one or two casinos. Side bet strategies usually involve using basic strategy, some type of balanced or unbalanced counting system like Hi-Lo, and one or more side counts for whatever card or cards the game warrants.