Not sure what meaningful conclusions you can draw from this. In my experience what makes a post popular is something like 50% content, 25% title and 25% timing. That's a lot of variance, I imagine with different wording and/or timing of the submissions your results might have been dramatically different. I've definitely seen posts that go nowhere the first day but go but the top of the front-page when it's re-posted verbatim or slightly reworded by someone else.
I would say the conclusion is pretty much what you said. 50% content, 40% title and 10% timing makes a successful post. (obviously for break news/trending events timing is everything - my focus was on content that could be leveraged at any time)
