If we're talking about an adult beginner who loves the game and plays pretty regularly but doesn't "work" on his game, I would expect him to reach like ~1700 FIDE after 5-10 years of regular practice.
If he gets regular feedback in analysis from stronger player, he could go higher, maybe 1900-2000 ?
Thanks for that input. I did find the 2300 claims a little hard to believe. Recently there was this news about an African girl from a shanty town in [I can't remember which country] who discovered the game by chance while looking for food and took so naturally to the game that she is now African women's champion or something. That's the kind of person I'm talking about, though she had a coach. She played in some international tournaments and did reasonably well, but a GM commented that she has some way to go before mastering the game. I got the impression about 2000 FIDE from those comments.
talent is only what you make it!...many ladies have natural talent with a different set of numbers altogether
Here's a video of Phiona Mutesi if you haven't seen this:
A coach certainly makes a huge difference for someone who doesn't work on his chess, as it's a way to get regular feedback on your play. But are you sure the lady wasn't working on her chess at all ? For example, simply solving a couple of tactics every day for 10-15 minutes makes a huge difference after a couple of years...
If you are talking about chess, that's hard to have a benchmark. So I will give you other examples.
Even Einstein had to get his PH. D. Even Wolfgang Amadeus who played piano on one look only had to have a mentor. Same with Beethoven.
A raw talent is like unsharpenened knife. It can't cut, and somewhat useless.
There are many prodigies in the world that don't a chance to their talents. To be successful, a person has to have the right ingredients. Like a cake. It has to be made of 1st class flour. If 2nd class flour is used it can't be the best cake. And it has to be 1st class cook using 1st class flour to make the best cake. If 2nd class cook uses 1st class flour, it may not be the best cake.
The flour is associated with raw talent. It has to be 1st class. Other ingredients are associated with the environments, teachers, friends, parents, emotion, etc.
So it takes a lot to sharpen the raw talent into 1st class chess player.
No you're right, cos she was definitely working with her coach. So she's not really a theory-free player, though she did attain her current level pretty fast.
According to FIDE's website, Phiona Mutesi's FIDE rating is 1686, so I guess she won an African youth title.
Just remember that a 2300 chess.com player often have a FIDE rating about 2000.
You need to know some opening theory and tactical sequences