Blackjack - Shuffle tracking

There are well-established techniques other than card counting that can swing the advantage of casino blackjack towards the player. All such techniques are based on the value of the cards to the player and the casino, as originally conceived by Edward O. Thorp. One such technique, mainly applicable in multi-deck games (aka shoes), involves tracking groups of cards (aka slugs, clumps, packs) during the play of the shoe, following them through the shuffle and then playing and betting accordingly when those cards come into play from the new shoe. This technique, which is admittedly much more difficult than straight card counting and requires excellent eyesight and powers of visual estimation, has the additional benefit of fooling the casino people who are monitoring the player's actions and the count, since the shuffle tracker could be, at times, betting and/or playing opposite to how a straightforward card counter would.

Arnold Snyder's articles in Blackjack Forum magazine brought shuffle tracking to the general public. His book, The Shuffle Tracker's Cookbook, mathematically analyzed the player edge available from shuffle tracking based on the actual size of the tracked slug. Jerry L. Patterson also developed and published a shuffle-tracking method for tracking favorable clumps of cards and cutting them into play and tracking unfavorable clumps of cards and cutting them out of play. Other legal methods of gaining a player advantage at blackjack include a wide variety of techniques for gaining information about the dealer hole-card or the next card to be dealt.

Card tracking is restricted when the casino uses a half-cut, or what is known inside houses as 'The Big C'. This is when the shoe is cut halfway, meaning that only half of the shoe will be played, so on an 8-deck shoe, only 4 decks will be played and thereafter shuffled. As card tracking relies on the principles of elimination, the half-cut makes it virtually impossible to eliminate or predict the remaining cards. Another exception to card tracking is the introduction of automatic shuffler machines, thereby making it impossible to track cards because the shoe is non-stop.

From Wikipedia's