Samboka primarily. Judo doesn't work much in the MMA. Albeit Sambo is basically just Judo+wrestling+some basic striking (combat sambo).Fedor is a grappler who can strike, too. Although at the end of his career his grappling significantly degraded, I think due to his back injuries, so he fell in love with his hands more. Early in his career he was a legit near-world class judoka, who didn't make it to the world class level because there were like one or two guys better than him in Russia.