Advanced advantage techniques

Beyond card counting sit a handful of techniques that extract more information from the same game: shuffle tracking and ace sequencing follow specific cards through the shuffle, hole carding exploits a dealer’s exposed hole card, and edge sorting reads the backs of the cards. They range from clearly legal to judicially condemned, and the Phil Ivey cases give the clearest modern account of where courts draw the line. This page describes each at the level needed to understand what it is and how the law treats it; it is not a manual.

The spectrum from counting to cheating

Wikipedia’s advantage gambling article lists card counting, hole carding, shuffle tracking and edge sorting as ways blackjack “can sometimes be beaten”, and states the general principle: advantage play is not illegal because the player follows the rules of the game, but it may result in being banned. The operative question in every technique below is whether the player is only observing what the casino’s own procedure shows them, or whether they are altering the game or using aids. Observation is advantage play. Alteration and aids are cheating.

Shuffle tracking

Wikipedia describes shuffle tracking as following groups of cards through a series of shuffles, used alongside card counting and most often in six- and eight-deck shoe games because their simpler shuffles are easier to follow. The player notes the Hi-Lo count of selected sections of the discards, called tracking zones, watches where those sections land during the shuffle, and then cuts a high-card zone into play, or a low-card zone out of play, and bets accordingly.

The idea is that a casino shuffle is not random: it is a procedure of riffles and strips that moves slabs of cards in roughly predictable ways. If a slab known to be rich in tens and aces can be located after the shuffle, the player has a positive count before a single card is dealt. Wikipedia credits Jerry Patterson with publishing material on the technique in the 1970s and 1980s.

It is a counting technique on top of counting, demanding and hard to distinguish from ordinary play, but entirely at the mercy of the shuffle procedure; modern multi-pass shuffles and batch shuffling machines were introduced largely to defeat it. How a shoe game is dealt describes what a shuffle looks like from the player’s side.

Ace sequencing

Ace sequencing is a narrower cousin of shuffle tracking. The player memorises the one or two cards that precede each ace as the discards are collected, and if the shuffle keeps those small groups together, the appearance of a “key card” during the next shoe predicts that an ace follows. A player who knows an ace is about to arrive as their first card has a large, temporary edge on that hand because of the 3:2 payout on naturals.

Legally it is in the same category as shuffle tracking: pure observation and memory. Practically it depends even more on a shuffle that preserves adjacent cards, which is exactly what modern shuffle procedures are designed to break.

Hole carding

Wikipedia defines hole carding as obtaining knowledge of cards that are supposed to be hidden from view. In blackjack that is the dealer’s hole card, and a player who knows it can play the hand almost perfectly: stand on 16 against a dealer 20, hit a 19 against a 20, and so on. The technique applies equally to other games with a hidden dealer hand such as three card poker and Caribbean stud.

The article’s legal summary is that in most jurisdictions hole carding by observation is a legal form of advantage gambling. The player is sitting in their seat and looking at what a careless dealer shows them. Methods in that category include watching the card as it is slid under the upcard, “first basing” (sitting at the seat with the best angle when the dealer checks for blackjack), reading a partial corner, and reading dealer tells.

Excluded, and treated as cheating, are mirrors or other devices, touching the dealer’s cards, and having another person read and signal the card. The article names “spooking” as the collusion method where a partner with a better view peeks and communicates the card. The line is the same one that runs through this whole page: your own eyes from your own seat are legal; help is not.

Edge sorting and the Ivey cases

Wikipedia describes edge sorting as observing, learning and exploiting subtle unintentional differences on the backs of the cards. Some decks have patterns that are not perfectly symmetrical, so a card rotated 180 degrees looks very slightly different along one edge. If the high-value cards can be rotated one way and the rest the other, the player can tell a high card from a low card face down. The player achieves the rotation by asking the dealer to turn particular cards, typically citing superstition, and relies on an automatic shuffler that does not rotate cards to preserve the sort.

The two Phil Ivey cases are the authoritative test of whether this is legitimate.

Crockfords, London. In 2012 Ivey won £7.7 million at punto banco (baccarat) using edge sorting with a partner, Cheung Yin Sun. Crockfords returned his £1 million stake and withheld the winnings. The High Court found that edge sorting was cheating for the purposes of civil law; the Court of Appeal dismissed his appeal in 2016; and on 25 October 2017 the UK Supreme Court unanimously ruled for the casino. The court held that dishonesty was not a necessary element of cheating, and that Ivey’s genuine belief that edge sorting was legitimate did not matter. Its reasoning turned on the fact that Ivey had used the croupier as an innocent agent to arrange the cards: he had not merely exploited a flaw in the casino’s procedure, he had caused the flaw.

Borgata, Atlantic City. In the same year Ivey and Sun won about US$9.6 million at baccarat at the Borgata. The casino sued in April 2014. In December 2016 US District Judge Noel Hillman ruled that the pair had not committed fraud and had not broken the rules of baccarat, but had breached their contract with the casino by violating the New Jersey Casino Control Act’s prohibition on marking cards, and ordered the return of about $10.1 million, a figure reported by PokerNews and including craps winnings staked from the baccarat money. Ivey appealed to the Third Circuit; Wikipedia reports that after oral argument in 2019 the court referred the parties to mediation and that a settlement was reported in July 2020.

The common thread is important for every technique on this page. Both courts accepted that Ivey had neither touched the cards nor used a device; what condemned the play was that he had arranged the game state through the dealer rather than observed it. Wikipedia’s edge sorting article notes that the UK ruling would not apply to a player who simply took advantage of an anomaly in the deck for which they were not responsible.

Where the line sits

Drawing the techniques together:

• Legal and tolerated as skill: card counting, shuffle tracking, ace sequencing, observational hole carding. Casinos may still exclude you for all of them in most jurisdictions; see casino countermeasures and legality.
• Cheating in every jurisdiction: any device, any confederate reading hidden cards, touching or marking cards, dealer collusion. Nevada’s device statute, discussed on the countermeasures page, criminalises even possession with intent.
• Contested but resolved against the player: edge sorting that depends on inducing the dealer to sort the deck. Two legal systems reached the same answer by different routes.

None of these techniques is a plausible route to income for a recreational player: each needs game conditions casinos actively remove, each attracts more scrutiny than counting, and the one with the largest documented win ended with the money returned. Their value to an ordinary player is understanding why casinos run shuffles, card handling and surveillance the way they do.

This page concerns real-money casino play and the law as reported by the sources cited; it is not legal advice. Blackjack World Tour is a free iOS blackjack game played with virtual chips; it is a social casino with in-app purchases and no real-money gambling.

Related reading

• Casino countermeasures and legality
• Card counting overview
• Famous blackjack players
• How a shoe game is dealt