Like any performance, timing plays a role, quality plays a role, and luck should not be discounted.
However, one should not mistake what passes for entertainment on other websites for what people want from HN and are likely to reward. In general, HN expects accuracy and rewards insight and good writing. It definitely punishes trying to create inside jokes and exclusionary cliques (see PG's essay about high school).
So long as it is of high caliber, wit may be rewarded. The same is true to a lesser extent of sarcasm and even snark. My personal rules of thumb are: snark only if what I have to say is emotionally important enough to take the downvotes and karma hit in stride; avoid sarcasm in general; and if I am not sure something is really witty to forgo posting it.
With any type of comment, I am willing to delete it if it isn't going to accomplish my goal or add to the community...and yes, sometimes my ego is at odds with what adds to the community. Hopefully, that is less and less the case.
As far as submissions, I have had my most success with more technical articles and blogs, less with opinion pieces. Largely, getting a good article to the front page is a matter of luck for me.