It's not him. (Score 4, Informative)

As one of the players profiled in BDTH, I can say with authority that Bill Kaplan is definitively NOT the basis for the Mickey Rosa character in the book nor the character that Mr. Spacey plays on screen.

While I will not comment on any of the rest of Mr. Kaplan's claims, I will say that, following the release of the book, and especially given the success of the movie, there have been several people who may or may not have been active card players at that time that have come out to falsely claim that the book is about them.

Lest you suspect I may be one of them, I will point out that I was the one who submitted the original WIRED story to slashdot several years ago.