Is Phil Ivey one of the world's best poker players, or a cheat who swindled almost $10 million from Atlantic City's Borgata Casino?

Borgata is suing Ivey in federal court, claiming the professional poker player and an associate took advantage of a defect in the playing cards to win $9.6 million from the casino over four occasions in 2012.

Another lawsuit, filed in England last year, claims Ivey and an accomplice pulled the same stunt to win nearly $12 million from a British casino. Ivey has denied those claims.

So, how did Ivey do it?  Borgata's suit claims he was able to spot tiny variations in the pattern printed on the backs of the cards in a method called “edge sorting”.

According to the New Jersey Law Journal, "the suit—with counts of breach of contract, fraud, conversion, unjust enrichment, civil conspiracy and racketeering— also names card maker Gemaco Inc, which made the allegedly defective cards, and Cheng Yin Sun, who accompanied Ivey on his trips to the Baccarat table and gave instructions to the dealer.

Ivey, whom ESPN and USA Today have called the world’s best poker player, contacted the Borgata in April 2012 to arrange a visit to play Baccarat. He agreed to make a $1 million deposit to a maximum bet of $50,000 per hand.

At his request, Borgata provided a private “pit” in which to play and a casino dealer who spoke Mandarin Chinese. Ivey was allowed to have Sun at the table while he played and to have an automatic card shuffling device used.

It is the automatic card shuffler that makes edge sorting possible, because it keeps all cards facing in the same direction. A dealer shuffling the cards by hand would turn part of the deck.

During a 16-hour session at the table on April 11, 2012, Ivey won $2.4 million. Sun sat with him and she gave instructions to the dealer in Mandarin on how to lay down and flip over the cards.

On May 3, 2012, Ivey and Sun returned and requested the same arrangements. Ivey played a total of 56 hours and won $1.6 million. On July 26, 2012, he returned again, playing 17 hours and wining $4.8 million."

At the end of each session, Ivey had the casino deposit his winnings in a bank account in Mexico, where he lives.

When he returned for another session on Oct. 7, 2012, Borgata personnel confronted him with media reports that he had engaged in edge sorting at a casino in London and won 7.8 million pounds, or about $12 million, in a single session in August 2012.

Ivey is tied for fourth for most career World Series of Poker bracelets.  He has earned more than $6milliion at World Series of Poker events.