He is known for his career in Fighting Network Rings and for his role training several Dutch Mixed Martial Artists and Kickboxers, among them Bas Rutten, Alistair and Valentijn Overeem, Gilbert Yvel and Gegard Mousasi.
Reportedly, Dolman had no sambo experience, having watched his first practice session of the art two days before the event, and still he dominated the tournament with just his judo and wrestling training.
[4] His first visit to the Japanese rings was in 1976, backing Willem Ruska during his professional wrestling match against Antonio Inoki in New Japan Pro-Wrestling.
Leading a stable of Dutch apprentices, which included Dick Vrij, Gilbert Yvel, Valentijn Overeem and other names, Dolman became Maeda's first rival in Rings.
He would win the inaugural Rings Mega Battle Tournament in 1993 defeating Maeda in the finals, although the Japanese got revenge on him eliminating him from the 1993 edition.