Ok, that's a good point. I assumed poster quality mattered because posts which are highly rated are mostly from posters with high karam. Confusing cause with effect probably.

That said, the quality of the titles matters a lot, and getting some up votes quickly also seems to mater a lot. Users could be bad actors and intentionally do bad titles. They also can try to avoid collect early votes through timing their posts during the weekday morning west coast time. I suspect that hacker news traffic peaks wednesday at lunch time PST.