From MMA junkie article:
According to the unified rules that D’Amato and other judges rely on, a 10-8 score “does not require a fighter to dominate their opponent for 5 minutes of a round.” A 10-8 score should be awarded if “one fighter has dominated the action of the round, had duration of the domination and also impacted their opponent with either effective strikes or effective grappling maneuvers that have diminished the abilities of their opponent.” A 10-8 score should be considered if “a fighter IMPACTS their opponent significantly in a round even though they do not dominate the action.”
This is really broad, think it leaves a lot to interpretation..
Doesn't judging in every sport suck though?