Advantage play is a term used in the casino business for someone that tries to take advantage of a dealer or casinos weaknesses. Poor game protection procedures, laziness on a dealer's part and awareness by a player can all help change the odds of a game from a house edge to a player edge.
The following are ways that advantage play can be used to put the odds in your favor. These are not cheating methods. Cheating is against the law and will get you arrested. These are methods of taking information that is given to you and using it to your advantage.
Card counting is one of the most common forms of advantage play where the player is takes information given to them and uses it to their advantage. The card history during play is the information given and adjusting bets based on this information is where the player gets their advantage.
Card counting was explained in a previous post and is relatively easy to learn. The basic theory of card counting is that as the cards come out, you keep track of how many low cards (2-6), ones that help you when they've been used have been used up, how many high cards (10 - A), which hurt your chances when used and how many middle cards (7-9), that have no real effect on betting.
Although not appreciated by the casino, card counting is legal in every casino. And if found, you will most likely be asked to leave. If not asked to leave, the casino may employ a few tactics to counteract the counting. They could require you to "flat bet", meaning you must bet the same amount every hand throughout the shoe. They could shuffle the cards anytime you increase your bet. They could also reduce the betting spread on the game. What was once a $25 - $500 game could be reduced to a $25 to $100 game.
Hole carding is when the dealer exposes cards on the bottom of a pack of cards or single cards as they comes out of the shuffler or shoe. Hole carding can be done on most poker based table games and can really swing the odds in the player's favor on Three Card Poker, Ultimate Texas Hold'em, Heads Up Holdem, Crazy4Poker and a few others.
An example of whole carding on Three Card poker might be that when the dealer takes the cards out of the shuffler and is delivering the cards to the players and dealer, as the cards are being lifted from the shuffler to be given out, the cards can be lifted too high off the table where the bottom card of the pack of 3 cards can be seen.
If the dealer exposes their own bottom card each round, the house edge on the Ante/Play bet goes from 3.4% in favor of the house to 3.5% in favor of the player. Knowing the whole card changes the basic optimal play drastically. Normally, without any knowledge of cards, Q64 or higher should be played and Q63 or lower should be folded. By seeing the hole card is a 2-J, the play bet should always be made. If the hole card is a Q, then Q92 or higher should be played. If the hole card is a K, then K92 or better should be played. And if the hole card is an Ace, the A92 or better should be played.
This is a pretty simple strategy to learn and if the hole card is being exposed every hand by a certain dealer, you will have a 3.5% advantage during that time.
Edge sorting is a little bit more controversial than Hole Carding because you are not just using information given to you. Edge sorting, you are actually taking advantage of a flaw in card production and turning the cards that you handle based on if they are advantageous for you or not.
Many casino card companies produce cards with designs on the back that are not perfectly symmetrical. As you can see from the example below, on the bottom of the card pictured there is a full circle visible in the pattern before it hits the edge. On the top you can only see a half circle.
So, if the casino does not do a proper shuffle after each hand, which would include turning half of the cards prior to shuffling, a player could turn all the face cards in one direction and all the non-face cards in the other. It would take some time to get through the entire deck, but once complete, the player can then know the approximate value of dealer cards. In a game like Three Card Poker, the player could know 1, 2 or all 3 of the dealer's cards. In Ultimate Texas Hold'em, the player could know if either or both of the dealer's cards are face cards. This knowledge of the dealer's cards could be a huge advantage to a player in these and many other games.
Sharing information in table games is almost always prohibited in the rules, but many casinos are very lax on enforcing the rule. Friends playing together and enjoying themselves often look around or flat out share what they have with others at the table. It is so common these days that someone taking advantage of this lack of game protection can easily blend in to the crowd and not be noticed.
Sharing information on a game like Ultimate Texas Hold'em can create a 2.5% player advantage. This could be attained by sitting in the middle of the table and looking at all other players 2 card hands dealt to them or it could be done by some sort of signaling from other players in on the play. One player makes very large bets and is signaled by all the other players at the table, who are just placing table minimum bets.
An example of how this could work is if the player receiving the information got dealt a Q 8. Without shared information, Q 8 is always a 4x raise. There are obviously chances to get Q on the board and also a possibility of drawing to a straight. But what if the other 5 players at the table signaled their cards and they included two Q's and some 10's and J's? Now the chances of hitting a Q on the board or getting a straight are drastically reduced. There is no way the player should place a 4x bet with that knowledge. Conversely, a dealt hand like J 7 is never a 4x bet pre-flop. But, if all players signal and every card in a player's hand is below 7, the chances for a straight or 3 of a kind or even better are hugely increased. This would be a perfect time to bet 4x.
As you can see, nice advantages can be gained using advantage play techniques. Most of these opportunities arise when the casino does not follow their own game protection rules. It is very easy or a casino to avoid these situations, but laziness and lack of pride in ones work are common place in the casino environment and allow for these situations to go unnoticed and taken advantage of.