There's a smattering of information on disembowel and lots of assumption, but I'm curious what makes Dark Elves so good at disemboweling, and what other races might excel at it (in particular for PVE). So what are the known or probable factors for disemboweling?

Str, Dex, Wis, Int?
Size?
Speed?
Legacies? (I feel like STSF Help)
Luck?
Skill (no brainer)
Others?