https://gist.github.com/SMUsamaShah/e7c9ed3936ba69e522f8cb38... This userscript (can use as a bookmarklet) lets you catchup to all unseen stories quickly. Open HN, click bookmarklet, any new stories will be appended with a "(NEW)". Old stories, will show much their rank was changed. Can set a flag to hide seen stories, or set comment and points threshold to hide/show old stories.

To me it makes it very quick to catchup. I just go over a few pages and can quickly see every new story that I have not seen yet.