To say that the story of "America's greatest hustler" is like Damon Runyon is something of a tautology. The real Runyon weaves in and out of the book, notably when he observed Thompson's involvement in the murder of Arnold Rothstein, who crops up in The Great Gatsby for fixing the World Series of 1919.
Thompson didn't shoot Rothstein, though he did kill five others. His response when asked the limit in a poker game – "The sky's the limit" – gave Runyon Sky Masterson's name. But it wasn't a bet when you were against Thompson: you were going to lose. He took Al Capone for $500 in a bet on throwing a lemon. This hardboiled yarn is pushed as "a terrific read for anyone who has ever laid a bet", but its lesson is: don't.