What is Edge Sorting?

Edge sorting is reading the back of a playing card to work out roughly what is on the front. It needs a deck whose back pattern is not quite symmetrical, a dealer willing to turn certain cards around, and a shuffle that does not undo the arrangement.

It made the front pages because Phil Ivey used it to win £7.7 million at Crockfords in London and $9.6 million at the Borgata in Atlantic City, and then lost both in court. The UK case went to the Supreme Court and ended up changing the test for dishonesty in English criminal law.

Here is how it works, what the courts actually decided, and why it is close to impossible today.

The technique depends on a printing flaw. On some decks the pattern on the back is not perfectly symmetrical, so the design runs slightly closer to one long edge than the other. Every card in the pack shares the same flaw, which is what makes it usable: a deck with an asymmetrical back pattern is vulnerable when that pattern is identical on every card.

Turning the Cards

Spot the flaw and you still know nothing, because every card looks the same. The value comes from getting the high cards turned the other way up. A player asks the dealer to rotate particular cards, usually dressed up as superstition, and from then on those cards are physically distinguishable from the rest while still face down.

The Shuffle Is the Whole Game

This is the part almost every account gets wrong. The sort only survives if nothing re-rotates the cards, so the player has to ask for an automatic shuffler. A machine shuffle preserves orientation. A manual shuffle, where the dealer turns halves of the deck around, destroys the arrangement completely.

So the request is not for hand shuffling. It is for the machine, and for the same shoe to stay in play.

Baccarat, and its Punto Banco variant, suits the technique better than anything else on the floor. The reasons are structural rather than mathematical.

Cards are dealt face down, players never handle them, and the sequence of play is rigid enough that a rotated card stays where you expect it. Baccarat is also the one game where elaborate ritual is normal, so asking a dealer to turn cards a particular way attracts far less attention than it would anywhere else.

Why Knowing the First Card Matters So Much

You do not need to know the exact card. Knowing whether the first card off the shoe is likely to be high is enough to shift the odds on which side to back, and Baccarat starts from a low house edge anyway. A small informational advantage on a thin margin is a real advantage.

Phil Ivey, a poker player with ten World Series bracelets, ran the technique at two casinos in 2012 with Cheung Yin “Kelly” Sun, who identified the flawed decks. Neither of them touched a card, used a device, or broke a stated rule.

Crockfords, London

Ivey won £7.7 million at Punto Banco over two days in August 2012. Crockfords did not pay, believing he had cheated by edge sorting and by persuading the croupier to keep the used decks in play. Ivey sued to recover the money.

He lost at every level. In Ivey v Genting Casinos (UK) Ltd t/a Crockfords [2017] UKSC 67, decided on 25 October 2017, the Supreme Court held the technique amounted to cheating, so the implied term in the gambling contract had been breached and the winnings were not recoverable.

The Borgata, Atlantic City

Ivey and Sun won $9.6 million at baccarat at the Borgata the same year. The casino sued, and in 2016 a federal judge ordered them to repay $10 million. Judge Noel Hillman found that they had not committed fraud, but had breached their contract with the casino by falling foul of a New Jersey provision against marking cards.

The Bit That Outlived the Baccarat

The dispute was about a contract, but the Supreme Court used it to address the criminal law test for dishonesty. Lord Hughes held that the long-standing Ghosh test does not correctly represent the law. A card game in Mayfair changed how English courts decide whether anybody, in any case, has been dishonest.

Edge sorting sits in the same argument as whether counting cards is cheating, and the courts have now answered one of them.

Casinos and advantage players give opposite answers, and after 2017 only one of them is the law.

The player’s case is that nothing was marked, nothing was touched and no rule was broken. Every request Ivey made, the dealer was free to refuse. On that reading it is observation and persuasion, which is what advantage play has always been.

What the Court Actually Said

The Supreme Court did not accept it, and the reasoning is worth being precise about because it is widely misreported. Ivey was found to be honest in his own mind, and the court took him at his word. It made no difference, because the judgment held that dishonesty is not a necessary ingredient of cheating. He had taken steps to fix the odds in his favour, and that was enough.

So it is not that he cheated dishonestly. It is that you can cheat honestly, and still not get paid.

Realistically, no, not in a regulated casino.

The countermeasures are simple and they are now standard. Card manufacturers print backs with rotational symmetry, so turning a card changes nothing. Dealer protocols discourage rotating cards on request. And a manual shuffle, or a machine that turns cards, wipes out any sort that did get established.

Where the Conditions Might Still Exist

Any table using an older or cheaper deck with an asymmetric back, dealt by someone willing to take instruction. That is a shrinking category and it is not one you will find on a regulated floor with modern cards.

And the legal position has moved. Before 2017 a player could argue there was no rule against it. After Ivey, a UK casino has a Supreme Court judgment saying it is cheating and it does not need to prove dishonesty to keep your money.

Edge sorting is one of several ways players have tried to get an edge, and it is the one with the highest ceiling and the highest risk.

• Card counting: tracks the ratio of high to low cards left in a Blackjack shoe. Legal, purely mental, and the edge is under 2%.
• Hole carding: seeing a card the dealer accidentally exposes. Depends on someone else’s mistake, so it cannot be planned.
• Shuffle tracking: following groups of cards through a riffle. Only works on hand shuffles, which is the opposite of what edge sorting needs.

The difference is scale. Counting grinds out a fraction of a percent over thousands of hands. Edge sorting, when the conditions line up, moves millions in two days. It also ends in court, which counting does not.

The documented record is smaller than the legend suggests. Two cases have been through court and produced findings you can actually read, and both are Ivey’s.

What the Borgata Case Established

The New Jersey ruling turned on something more interesting than the money. The judge found no fraud, but held that the pair had breached their contract with the casino by running foul of a provision aimed at marking cards. Nobody had drawn on a card. The court treated making cards distinguishable, by any means, as the same problem.

That is the reasoning other casinos would rely on, and it is why the technique is a legal dead end rather than merely a difficult one.

Casinos do watch for it, though the useful countermeasures are duller than the surveillance story suggests.

The ones that actually work are physical: symmetrical card printing, which removes the flaw the technique needs, and dealer protocols that decline requests to rotate cards. Neither depends on spotting a player in the act, which is why both are effective.

Why Monitoring Comes Second

Watching for unusual bet patterns or repeated requests about a particular shoe can flag a table for attention. But by then the sort already exists. Fixing the deck stops the technique before it starts, and that is where the industry put its effort after 2012.

Private and unregulated games are where the conditions could still exist: older decks, hand dealing, and no surveillance worth the name.

The trade-off is that the protections disappear with the oversight. In a licensed casino a dispute is a legal argument with a regulator behind it, which is how Ivey came to have his case heard by the Supreme Court at all. In a private game there is no such route.

The response since 2012 has been unglamorous and effective.

• Backs printed with rotational symmetry, so a turned card looks identical
• Table protocols that limit what a player can ask a dealer to do with the cards
• Shuffle procedures that re-randomise orientation between shoes
• Attention to repeated requests around a single shoe rather than to the betting alone

The first item on that list is the one that matters. If the deck is symmetrical, everything else is moot, because there is no flaw left to read.

Closer to finished than dying. The technique was never widespread; it needed a specific manufacturing defect, a compliant dealer and a machine shuffle, and the industry removed the first of those.

What survives is the argument. Ivey did something clever with public information and no equipment, and lost anyway, because the courts decided that arranging the odds in your favour is cheating whether or not you think you are being honest about it. That question did not go away when the decks changed.

Edge sorting is not a strategy anyone can use now. It is the clearest case study in gambling of where advantage play stops being clever and starts being actionable.

Ivey won £7.7 million and $9.6 million, kept neither, and left behind a judgment that English courts now apply to dishonesty cases that have nothing to do with casinos. That is a strange legacy for a fortnight at a baccarat table.

The practical lesson for anyone reading this as a player is smaller and duller. The line is not drawn at rule-breaking. It is drawn at whether you took steps to change the odds, and you can cross it while behaving, by your own lights, entirely honestly.