I've had front page stories on HN maybe five or six times over the last couple of years. I don't feel anything has changed over that time. If you look at my submission history, you'll see about 90% of what I submit gets no votes. I once tried submitting a story a couple of times when I felt that it was getting less traction than expected - it made no difference.
I'm actually surprised at how well HN surfaces decent content (I'm quite happy to accept that my stuff which got no upvotes just wasn't of interest.) Whenever I put something up it gets about twenty eyeballs off the 'New' page so real people are looking at it.
I can say for sure that I don't have any friends with HN accounts (much to my disappointment!) and I've never tried to game it.