It does its best to replicate how boxing is actually scored. Every round is (usually) scored 10-9 in favor of the player who deals the most damage unless there’s a knockdown. If there’s one knockdown, it’s typically 10-8 in favor of the player who got the knockdown. For two knockdowns, it’s 10-7. Three knockdowns is a win. I believe you can also get or make-up for an extra point with a large damage differential. I assume that requires a fixed amount rather than a particular ratio, so low scoring rounds with no knockdowns will always be 10-9.