What made that one special?
I never expected this one to be upvoted well over 100 times: https://news.ycombinator.com/item?id=47849520
Sometimes you post at the right time for people to see it and it gathers enough attention to hit the front page. Once it's on the front page, and if it's a really good submission, it can stay there for hours.
But, you really can't tell which submission will be a hit or not. The ones you're certain will blow up can go unnoticed.
It's something I drafted in a single evening that suddenly gets into top-3 traffic acquirers for my blog.