Not sure when it started, but the second chance pool has moderators putting stories that didn’t get much attention when they were submitted directly on the front page.

There may be some survivor bias here, but second-chance stories seem very front-page sticky to me. At least those I have recognized.

It was started in late 2014 and dang explains how it works here:

https://news.ycombinator.com/item?id=26998308

I think I started getting Second Chance emails about ten years ago...give or take a couple of years.