You can do worse than James Swain's Deadman's Poker and Deadman's Bluff.
They're really two parts of the same book, about a poker tournament in which the big winner is surely cheating, but the protaganist can't figure out how. Along the way, we meet a 70-something professional gambler/grifter named Rufus Steele who manages to win millions from high rollers by winning a series of improbable bets. I'd say more, but I'd spoil it.
The books are part of a series by Swain featuring Tony Valentine, a former Atlantic City cop turned consultant for casinos who's an expert at detecting cheats. I always like to read about different worlds and the cheating stuff is fascinating in its own right.