Men’s Modern Gennadiy “GGG” Golovkin, the Kazakhstan-born champion, competed for 16 years from 2006 to 2022. He was the king of the middleweights for years, holding the WBA, WBC, IBF, and IBO titles. He faced a long list of elite fighters, including Danny Jacobs, Saul Alvarez, and Kell Brook, among others. Antonio Tarver – Florida’s Tarver, a 1996 Olympian, competed for 18 years, racking up the WBA (Unified), WBC, IBF, and Ring magazine 175-pound titles.