I have a decent eye for it because I've been there enough times. But it's not just a matter of being able to whether the other guy is stronger. I've beaten lots of guys who are significantly stronger than I am. But there comes a point where the combined product of the other guys technique and physical attributes is just more than I am going to be able to overcome. Without personal experience trying, I wouldn't know where that limit was.would hope that some who has a good sense of their limitations would know this before the match started. There are visual clues that determine that. The last time I was wrong about something like that was when I was 10. For me I'm more likely to think someone is stronger that what they are. By default I think my strength is weaker than what it really is and I think that's because what happened in the past. I'm always surprised how strong I am versus always being surprised that I'm weaker than I thought.
Definitely a mental issue for me because I'm like that with other things as well.
But back on point. I would think you have a good eye for experience levels and strength levels.
I've also discovered that some people are just way stronger than they look. Compared to other people of similar size and build, they turn out to be much more powerful once you actually feel them.