an ordinary chessplayer wrote on 08/30/19 at 03:41:37:

I like this book a lot thanks for the recommendation! I have the book in chessbase format. I was reading "Comprehensive Chess Endings 4". And I was stuck in the chapter "Development of the Theory of Co-ordinate Squares"
I would like to hear from you what other book recommendations you have for other areas of the games.
I need some guidance because there are so many books out there and they are not all of the same quality.

I cannot post a photo of some of the book examples due to copyright (or can I ¿), but there are many examples in the corresponding squares chapter with studies from Zinar. On the board has numbers 1, 2, 3, 4, etc. for White and for Black. 

Someone wrote about corresponding squares on their website. It looks something like this: 

https://www.ysifueraunapartida.com/finales-de-peones-casillas-conjugadas/#Las_ca...

Yes, Awerbach and Maizelis. White cover with "Pawn Endings" on upper left-hand part of cover with pictures of kings and pawns in foreground.

The chapter is called "Development of the Theory of Co-ordinate Squares". 

Subsections are:

1) Normal opposition
2) Triangular system
3) Eight square system
4) 'T' system
5) Some observations and conclusions

Many diagrams have numbers on squares for the corresponding squares, sometimes with "a" and "b" for critical zugzwang squares.

But what I mean is that this material is so confusing that I bet most GMs would have trouble understanding it. 

I read basically all books without the board, so that is not the problem. I try to understand how they number the squares and determine with "system" it is.

The reprint of this book, Comprehensive Chess Endings 4, has names of systems that sound like differential equations, like "quadratic", "first-order", "second-order". 

Maybe all of this is not necessary to fully grasp pawn endings, much less play this in OTB games when you have 30 seconds and 5 minute increment. But still, I would like to understand this thing.

I am reading Awerbach's last chapter of his Pawn Endings book, where he talks about corresponding squares in detail. He classifies it almost like a mathematics textbook, with "quadratic system", "T-square" and other terms.

But I am really having a hard time trying to figure out how to assign the numbers of these corresponding squares. Many examples go into sets of ten corresponding squares for White and Black. And even to do it, how possible is it to do corresponding squares analysis, remember where all the squares are and play this position in OTB games where you probably are in severe time pressure ¿

Is there a resource that can clearly explain theory of corresponding squares in pawn endgames ¿ 

I tried reading pawn book by Müller and the big tome by Авербах. The corresponding squares chapter I cannot comprehend properly no matter how slow I read them. I read same examples over three times, and still have no idea what the hell they are talking about. 

Most pawn books that cover this I end up confused on how they map out by 1, 2, 3, etc. which corresponding square is which, and why. I see diagram in book and think, so what was order of numbering the squares, and why there are duplicated corresponding squares. Maybe a wideo would be helpful but obviously Авербах cannot upload on YouTube