Game Mechanics: Rogue Backstab Damage

[Ravager]

Just want to throw in, I'm a 56 rogue and so far my largest backstab and coincidentally double backstab was a double 532. This was with Ragebringer and max strength, no avatar. It also happened in a duel death while key corpsing another rogue in sky and that person was sitting down at the time. I have yet to break 500 in any kind of mob fight, green or otherwise.