Do you believe that a guitarist who is self-taught and really dedicated to practicing can be as good or even better than a guitarist who was taught how to play by an instructor?

I'm self-taught and I know I'm better than a lot of folks who got lessons and weren't committed. Then again I'll probably never be as good as the best guitarists out there. I put my energies more towards song writing and improvisation than technical prowess. Either way, the biggest factor is how much practice you put in.

can be as good... yes... everyone has the potential... the thing about learning it yourself, is that you will come up with your own style faster than having an instructor teach you his/her style...

Oh I think you can teach yourself, become proficient, and then if you find your own style, become great.

There are two critical factors in becoming a top-notch guitarist (or musician of almost any sort):

1) Practice - Research indicates that it takes about 10,000 hours of dedicated practice to become world-class at a skill like playing musical instrument.

2) An early start - A person who does not start playing a musical instrument until after about age 13 has very little chance of becoming world-class. Neurological changes occur around that age that preclude someone from learning world-class skills unless they have already started.

Example: exceptional athlete and fanatical worker Michael Jordan could not learn to hit major league pitching, because he didn't seriously play baseball when he was young.

Also, it helps if your hearing isn't too sensitive....;-D....
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Some people are born musicians. They don't need lessons and can play circles around most folks.

yes