Even superstars can use an edge sometimes.

But in the world of high-stakes gambling, the edge between clever play and cheating can be thin and arguable.

Phil Ivey Jr. is one of the most renowned poker players in the world. He bills himself as the greatest professional poker player of all time. Now he’s fighting in court with two casinos that claim he cheated them out of a combined $22 million in marathon sessions of baccarat. In one case, the quality of playing cards made in the Kansas City area figure as a key factor.

A lawsuit filed last week claims Ivey took advantage of an alleged defect in cards manufactured by a Blue Springs company to cheat a New Jersey casino out of nearly $10 million.

And a British casino that withheld $12 million in winnings from Ivey for what it claims was the same type of cheating scheme is now being sued by the card player. Ivey maintains in that suit that he did nothing wrong and that the casino was at fault for allowing it to happen.

The cases provide a peek into the world of “high rollers” and the special consideration they get from casinos eager for their business.

The New Jersey suit stems from a series of four sessions of baccarat that Ivey played in 2012 at the Borgata casino in Atlantic City.

“Because of his notoriety as a high-stakes gambler, and the amount of money he intended to gamble, Ivey was able to negotiate special arrangements to play baccarat at Borgata,” according to the suit.

Those arrangements included a private game, an automatic card-shuffling device and a dealer who spoke Mandarin Chinese. Ivey was accompanied by a guest who, according to the suit, was a Chinese-speaking professional gambler named Cheng Yin Sun.

Ivey told the casino he needed a number of special arrangements to satisfy his superstitions.

But according to the suit filed in U.S. District Court in New Jersey, his real motive was to set the stage for a technique known as “edge sorting.”

“It is a strong technique that can lead to a considerable advantage over the house,” said Eliot Jacobson, a gaming protection consultant who holds a doctorate in mathematics.

Jacobson said edge sorting is a difficult method to detect that relies on imperfections in the geometrical pattern design on the back of playing cards. Ideally, the designs should be symmetrical so that the cards are indistinguishable from one another, Jacobson said.

But if the cards are not cut symmetrically during the manufacturing process, the two long edges of the cards will not be identical.

“In other words, one edge will have more of the geometrical pattern than the other,” the lawsuit explains.

Once the player ascertains that pattern, it allows them to recognize key cards in the deck before they are dealt and bet accordingly.

The Blue Springs company, Gemaco Inc., is one of a “select and small group of companies” that are “major players” nationally in supplying cards to the casino industry, Jacobson said.

But according to the lawsuit filed on behalf of Borgata, the Gemaco cards used for Ivey’s baccarat sessions were defective and not the “first-grade quality” the company promised.

Calls and emails to the company seeking comment were not returned for this article.

While cards with identifiable imperfections are necessary to pull off edge sorting, Jacobson said several other factors must be in place for it to work.

When the cards are shuffled, they cannot be turned or reoriented so that the edges always stay facing the same direction. That’s why Ivey requested an automatic shuffler, the lawsuit says.

Jacobson called that a “procedural mistake” on the part of the casino.

The player must also be able to have the cards rotated so that the edges of favorable cards are facing one way and unfavorable cards are facing a different direction throughout the playing session.

Jacobson called that a “challenging” hurdle for the player, who does not ever touch the cards during baccarat. Ivey was able to accomplish it by having his Chinese-speaking guest tell the Chinese-speaking dealer which way to turn the cards as they were dealt, the suit says.

The player also needs to be able to see the back of the card before making a bet. In the Ivey case, the suit says that was accomplished by having the cards dealt from a “shoe” where at least the back of the card can be seen before the dealer removes it.

In baccarat, the cards 6, 7, 8 and 9 are key cards. According to the suit, Ivey and his guest used edge sorting to differentiate those cards from others in the deck. If one of those cards is the first dealt, and the player knows it, he or she can bet accordingly.

Having that “first card knowledge” changes the game’s odds from a 1.6 percent edge for the house to a 6.7 percent edge for the player, according to the suit.

Jacobson described baccarat as a simple, “brain-dead game” that has a history of issues involving edge sorting.

An attorney representing Ivey did not return calls seeking comment for this article.

The game is particularly popular in Asia, and Jacobson said casinos there employ cards that are “considerably better” than those used domestically.

The easiest and most effective way to combat edge sorting is for the dealer to turn the cards while shuffling so that the edges of the cards are not always facing the same direction, according to Jacobson.

“That essentially fixes the entire problem,” he said.