According to my Backloggery:
Yellow: Completed (100% achievements or otherwise do everything the game offers)
Black: N/A (games with no completion point, such as purely multiplayer games)
Almost half of my unfinished games are unplayed ._.
So, about 49% beaten/completed, and about 24% started but not beaten, I guess that means I beat about 2/3 of the games I start.
Edit: Maybe I should elaborate on how these numbers come to be. I don’t like leaving games unfinished, but some games I only play with/for friends, and we rarely get the chance to play, which leaves those games unfinished for a long time. Some games I start and end up not liking, I still try to finish those, but they’re low-priority.
A lot of the time, I struggle to get through games that require time or effort to get into after downtime, or even just to boot up. The games I have the easiest time completing are ones I can launch and play on a whim while doing something else.
Many of the unstarted games are freebies or from the few bundles I’ve bought. A bunch are older console games that I don’t even remember how I got >>