Do you agreed?

In general

1. A beginner doent know about theory (<1000 rating)

2. Intermediate player knows theory ( 1000-2000 rating)

3. Advanced player knows the exception from theory (>2000 rating)

That being said, every stage has individual needs! and "One method doesn't fits all" .

There are a lot of people who discuss on this forum based on their own experience rather than the original poster's need!! 

Absolutely.

Myself included.
But sometimes I try to tailor it to the OP's need.

That's what a good coach would do.

By the way.

That's why it's useful to have a lot of opinions.

I may give a technically correct answer, but if a noob is coached by another noob, who understands the noob level better than I, then that might be the best advice. Or at least the most useful.

Pedagogy.

 It's also interesting to me the way skills are so related.

Whether it's chess or arts, or sports, or music, or etc.

The questions beginners ask seem basically the same.

The advice that helps people improve is basically the same.

I doesn't no agreed neither.

Theory is useful but much less important than you think. It makes no sense to study 100 opening lines that give you "a small advantage from the opening" if you don't know how you have to work with that advantage. And if you only know the theory but you don't understand anything about the middlegame that comes after that then 10 to 1 that you go make big mistakes very soon after you're out of book.

For me it works the best to know what I have to go for and look out for in the middlegame, and then find the way to get that battle on the board.

oh btw, you also make the mistake to think that rating says everything.

dear world

I dont want to sound slutty, but pleas use me whenever you can.

- Grammar

You have a point. Now look at the five mistakes you made in your letter.

Opening theory is very much overestimated, so the playing strength becomes much more important.

They tried this on Kasparov. They knew that he was a bigtime expert on the Sicilian, so they tried to force him out of book. Kasparov got 6 points out of 7 games with black because he was good enough to come up with a good plan on his own. His opponents: draws against Leko and Kramnik, points against Anand, Svidler, Ivanchuk, Adams and Topalov.

The 2500 player has much more experience and expertise in the game in general than the 2100. They have better positional understanding: where do their pieces go, what are the chances for the opponent, how will the position develop, etc. And probably they saw it at least one time before. So they probably find the right moves also without knowing the opening theory so well.