Would you like an in-game parser?

[Seraphix2407]

Better knowledge of the fight, better coordination with people you're used to raid with, jobs not optimized for the raid, and yes, gap in player skill.
But, among all that, I should also say...why does it matter ? Didn't they kill it too ?

You just proved my point. You just really did without realizing it. You see, just because you killed it, doesn't mean you did great hell even decent. I've put same lower dps in sephirot and we got enrage. I put one of the lowe dps in my own group and we killed it 2 min ahead of the enrage. Get my point? Many farm parties have gotten enrage because the dps wasn't enough and they all have gotten over 15-20 kills. But once they all gather in same party (low dps) they get enrage. This is my term of ''slack''. If you kill something doesn't mean you are great enough to do it with 3 other low dps people. Enrages speaks for itself.

Familiarity with the content to the degree that you could probably do it in your sleep vs a group of players that don't know the content or haven't memorized every singleminutiae, causing deaths and lost dDPS by mistakes that add up over the course of the instance. Not sure! I can't think of any reason in particular.

Keep in mind,many have killed it more than me if not much as me, so that leaves them having same knowledge as me in the fight. Losing 300-500 dps isnt a mistake, that screams you don't know rotation or you simply don't merge your rotation with the fight. Oh hold on, I thought SSS could do that?