Excelling at calculation by Aargard - Don't buy it

When you use chess books you are suppose to learn the ideas and not the evaluation. What i mean by this is the calculation in the book may be wrong, but the ideas contained in it are very practical and human, which ultimately will help you identify similar ideas in your own games. If you just look at eval and ignoring the ideas, you will learn nothing from the book. so yes, we are judging the 900 for critiquing a book that is still good despite its error

I would agree if this was a book about chess principles, or a book about strategy, but this is a book explicitly about calculation. If the author is going to demonstrate (and quiz readers on) calculating to the end of variations and choosing the "best" move, then the chosen move should actually be "best". In this day and age, the "best" move should either be the top engine move, or the author should give a clear explanation for why the move is better from a human perspective (e.g., results in an easier to play position) despite it not being the top engine recommendation.

Any way you slice it, it seems that the original poster's recommendation to avoid this book is warranted. Players below Class A strength are not the target audience and are unlikely to get much from this book, even if the analysis was correct. Players that are Class A and above are going to encounter frustrating examples where the author's recommendations deviate from the engine's analysis (and almost certainly their own) without sufficient explanation.

The first chess book I ever bought was “Calculation”, by Aagard. This was after overhearing a strong player at my club talking about how great it was. Well, I’m sure it is a great book, but it was way over my head then, and is still way over my head today. (I’m 1500 USCF in real life OTB games). 
But I don’t blame Jacob Aagard for this, or the strong player from my club. It’s all on me for buying something that I couldn’t handle.

One of the problems with much older books (that are not previously solved combinations) is that the evaluations can be way off, especially when they're just analyzing a complicated position rather than solving a problem with a forcing solution. Many books written around that time used engines like Hiarcs, Junior 8 or other old engines to help demonstrate who's better, but then you set up the position in Stockfish 16 and the evaluation is wildly off (even with complex positions judged by Grandmasters in something like older Chess Informants). Also one thing I absolutely HATE About Aagard's books (at least the book *I* have!) is that in his diagrams, he does **NOT** show who's on move! So if you're trying to set up a position blind, to do analysis on (Something Kotov recommended), you then end up having to see the move played just to see who's on move! Yikes.

I have just returned to Chess and my rating is still below 1000. I have not found Aagard's book to be "Over my head" I have all the Exceling books and his Positional Play book and have not had a terrible time with them. You just have to keep in mind that comparing his positions to Stockfish is a fools game. Often his position reflects a board several moves ahead and his position reflects positional creativity that Stockfish is not capable of expressing. Among many other factors. I doubt Aagard made a mistake.

When I come across positions I do not understand I research them until I do. If I still cannot resolve the position I take a note so I can refer back to it later when my education has caught up.

Computer evaluations are not really meaningful compared to treatment by a top GM, especially if he has computer evaluations himself. Stockfish could say -10 (black winning) and in terms of playing another human white have an overwhelming advantage and certain to win. Sometimes stockfish can spot some tactic 15 moves deep that are completely outside human perception, what is important is understanding a position and listening to what a good player thinks of it - not treating stockfish as some kind of ultimate truth.

I must admit that if every computer engine was saying something was bad, I might have some lingering doubts, but you're saying earlier computers that could easily beat any human are okay with it, yet stockfish 4000 elo finds a problem and so you will follow stockfish? You do know what stockfish says about your pet aggressive opening?

This is a good book for learning Calculation

i'm getting this book because of the theory on how to calculate

I also noticed something similar in his book Grandmaster Preparation_Calculation (page 16, Game : David Berczes - Hans Tikkanen, Stockholm 2010) where, to cover the black King from the check of Re6+, he opted for a losing move Rd6.

But I understand that Fritz he used on 2003-2004 is far from actual Stockfish. Moreover, even Kasparov had exactly same problem in his book "Kasparov on modern chess Part I"

So we don't have to blame them for that! They are teaching Ideas and concepts which are more important than engine's analysis.

8/5Rpp/p1k1R3/P1p5/7N/6P1/2p2PKP/3r4 b - - 0 1

I must add that neither the stockfish engine used by OP probably gave any explaination on the reasoning why what suggested differs from the move of the GM author of the book, or any other reasoning at all and even if it did, it would be very difficult for anyone short of a GM to follow the logic 15+ moves ahead, and most likely in a real human vs human game, the progression will be very different than what the engine foresaw.