Indicators for trade activity besides rating.
If there were an arrow or something similar next to the letter grade, that could open up more possible trades. I know I scroll past anyone who doesn’t have an A+ rating thinking, perhaps incorrectly, that they aren’t as active in the trading anymore and it would be a waste of a couple of days tying up cards in a trade. However, even if someone had a F rating but had an up arrow next to their rating showing they are actively trading again I would start throwing trades their way. This would also help knowing if someone with a B rating is a new person to the community (assume an up arrow) or someone who has gotten busy with life (sad down arrow). And someone like me who pretty much never logs out would either have a horizontal arrow or no arrow indicating no change.
I’d say this doesn’t have to be updated with every trade. Maybe once a day or something that makes sense to the software boffins. This could also be sorted on like rating or number of cards in a series. Again, you could find the people who may have lower ratings but are becoming more active.
Maybe this is too hopeful that the people with lower ratings are just very busy and haven’t forgotten about their accounts.