Just discoverd a tool and didn't see it mentioned here, so I thought I'd share
LosslessCut
It allows you to cut, split, merge videos without any reencoding / quality loss. It's a wrapper for FFmpeg and very user freindly.
I've used it to remove sections from videos (e.g. embedded ads

, content that I don't prefer) and export sections for a playlist of my favorite rounds. I know there are other tools that do this and members have created programs to manage rounds, but I found LosslessCut to be simple and straightforward for my needs, and free
You can
download for mac, win, and linux.