In 1969, he won the Texas Gamblers Convention in Reno, Nevada; it was there that the idea for the World Series of Poker was conceived.

[2] At the time, Addington was already a self-made millionaire[1] who played poker primarily for fun; for him, the game was more about personal challenge.

Addington participated in the first World Series of Poker in 1970 along with Amarillo Slim, Doyle Brunson, Sailor Roberts, Puggy Pearson, and Carl Cannon.

Although he was no longer an active player and had not had a tournament cash from 1990, fellow Hall of Famer Doyle Brunson described him as a "No Limit Hold'em Legend".

[citation needed] Addington was the CEO, Chairman, and Director of Phoenix Biotechnology, a company that focuses on cancer treatment research.