It's an interesting concept; perhaps a valid one.

But as an advanced-beginner/beginner-level intermediate student/player I'm not sure I have the experience or learning to identify 'virtuosos' or to do the "Rolling Stone" thing and rank the top 100 guitarists of all time and then re-order the list in terms of their teaching ability.

Studying the results of virtuoso guitarists who are good teachers, i.e., looking at sensei and gakusei, again surfaces my problem of determining who is truly good and has better results than the others. And if I am to learn who learned at the foot of the master where do I find that info...endorsements? Oooh...that sounds like a problem in the making.

Maybe another way to look at the guitarist-teacher to student results is to look at the opposite level -- the results of teaching those who started at the beginner-beginner level. Not the best guitarists, but those who started from nothing and moved to playing music for themselves, their family and friends and maybe even fans. Not superior technique, necessarily, but appreciated music. But then, I'm not sure how to study that either.

Anyhoo, while I won't be able to contribute to this I am looking forward to reading from those who have the learning and playing qualifications to do so.