Judging from Ziemba's publications -- he has consulted with Benter and other betting groups; is an expert in the mathematics of gambling, and has his hands in a lot of different areas -- Turkish flat weave rugs, financial trading using anomalies, investment consulting, hedge fund owner, horse race owner, financial and gambling author, academic publisher.
Knowing him and his friendship Harry Markowitz, who won the Nobel Prize for his work on portfolio diversification, Ziemba probably works with more than one betting team in order to be diversified.
By the way, the interview with Ed Thorp on "Chat With Traders" is also very good.
I wish the show host would also interview Bill Benter.