If they're at different skill levels? Whoever is more skilled.

If they're both at the same skill level but shit? The Knife, cause stabbing someone is easy, keeping someone back with a Bat isn't.

If they're both at the same skill level and actually good? The Bat because you can keep them back long enough to land a damaging below to the arm, head, leg, wherever you need to in order to paralyze them long enough for a finisher.