[Deltaray]

Spoiler for Stats:

It seems to be more like about your brains, for example Kirito has good reflexes (aka his brain works faster) which allowed him to get something special, not gonna spoil that here, but from what it seems it's not that big factor, it's more about what skills your choose, which makes combinations to get some other skills you wouldn't get otherwise, thats how I understood it from novels.