Auto-Filter Users by Game Completion Rate

Feature request:

I understand the Game completion rate keeps track of the percentage of games the user completes without abandoning. Whenever my opponent abandons the game in a lost position, I check their profile, and if this ratio is below ~90%, I block them, because I don't want to play with them if there is a 10% chance they will just abandon the game (1 in 10 seems huge to me). This happens frequently enough to be a bit annoying (I've blocked 60 players so far, and I don't block anyone unless they abandon a game).

I know that there are measures taken to limit this issue already, such as a temporary ban for letting time run out repeatedly (I think?) etc. I think these are great, and I'm sure they're greatly improving the experience for players already.

However, as an additional tool, it would be nice to be able to automatically filter opponents based on their game completion rate. This is how I imagine it would work:

- In the user settings page, a minimum opponent Game Completion Rate input that can be 0-100%
- Users who's game completion rate is below this threshold will be treated as blocked (i.e. won't be paired up with you)
- You can't set a minimum threshold that is greater than your own game completion rate (seems fair)
- This threshold defaults to 0%; users that want to opt in to this feature can adjust it as they like
- If a user's game completion rate improves above your threshold, they are automatically un-blocked again

The only drawback I see is that players with lower completion rates will find it harder to get opponents, but this is just an added incentive for them to finish or resign in their games. Besides, they can already be blocked manually, this setting would merely add convenience.

Advantages:
- Added convenience when blocking users that frequently abandon games
- Creates an incentive for other users to finish or resign their games, saving time and improving the experience for everyone
- Unlike traditional blocking, gives blocked users a chance to improve their game completion rate and get automatically unblocked again
- Unlike temporary bans, lets every user decide what an acceptable completion rate is - users with a completion rate of 70% can still play with others with a similar rate if they think that's fun, without bothering players that always finish games

I'm curious what others think. Would you use this feature? Are there any issues I haven't anticipated?

@rmazeiks

This sounds cool, but you should keep something in mind unless you already know. The game completion rate is calculated only for the last 30 games. So game completion rate might not be accurate to describe a player’s completion rate in general.

Say one day a player has Internet connectivity issues, and disconnects in 3 games out of 30 because of it. To you it looks like they leave games fairly often because you see a 90% completion rate, but in reality that player just had a bad time with their connection that day.

Check out Game Completion Rate of the best rated players on the lichess leaderboard! Do they like so much to abandon games in lost positions? No, they just sometimes abort games without playing.