I think it is more telling looking at battles challenged vs battles won though.
Not really.
That way I would have 99.11%.
Other than "testing for targets" battles there is very little reason to keep fighting somebody you're not mostly winning against, so challenged vs won will be quite high for the vast majority of people.
What's relevant is won (which is pretty close to challenged) vs total, which indicates how "farmed" you were during your character's lifetime. Ok, not necessarily really farmed, more like, how popular of a target you were compared to your own activity level.
People with relatively high percentages seem to fall in three categories so far:
* those with relatively low MPRs (they haven't started being attractive targets for too long, but most of them will, soon, and their percentages would be shot)
* people that started really early and maintained high MPRs (few people could consistently beat them during their lifetime)
* and last but not least, people with solid N*B strategies that ended up at high MPRs, which had very few tactical weaknesses to be exploited while growing (so again, few people could consistently beat them back then, and not many can beat them now)