On the anecdotal side, I think this and the Crouch book are helping me some. I was doing some game analysis with Laurent and a few others and I was able to come up with some aggressive/winning lines in the games that were very inspired by material I've covered in those books. I mentioned previously that I also considered Khmelnitsky's book. One thing I like is he has specific training recommendations for each subject. As it turns out, he recommends the Crouch book for Class A/B players to improve their ability to attack. So perhaps I'm on the right path.
Chapter 8 - Centralizing the pieces is much like chapter 3 on "basic opening principles". What sounds like a pretty easy chapter is actually a very difficult one on piece activity and the initiative. And just like chapter 3, I bombed the end of chapter exam, scoring only 4/27. Most of the problems are 2 or 3 star (very difficult). It certainly wasn't for lack of effort as I was considering multiple candidates and taking the entire 15 minutes on each problem. Sometimes I was close, but missed the right idea and several I had no real clue. I'm sure some of the moves I chose were fine, but they clearly weren't what was needed of the position. Of the 12 problems, 5 required you to play like Fischer and 4 required you to play like Rubinstein. Oh, is that all? :)
Chapter 9 - Mate in 2 is another misleading name. The goal here is to be able to calculate 3 ply accurately. Seems easy enough, right? All the lessons and exam questions are compositions. None of the positions would be relevant in an actual game. I personally hate this type of training and I almost skipped the chapter halfway through, but I decided to stick with it. I was pretty terrible in the example portion, but did much better with the end of chapter exam, scoring 7/12 which was enough for a pass with a point to spare. All of the problems are 1-star (easy), but most of them took me the full 15 minutes to solve. Like any composition, there is only 1 winning move, but you have to accurately see all of Black's replies and your reply to get credit. One problem had 16 variations!
Can you find all 16?
Chapter 10 - The opposition is what is says it is for once. Since it's K+P endgame related, I went in with high expectations. If you've ever done Pandolfini's Endgame Course, many of the examples would be familiar to you. Most of the exercises are practical compositions that you'd find in a real game. A mix of difficulty, including the first 4-star problem I've ever seen. The problems are hard but fair. On some problems, you have to see various tries by your opponent to pull off a swindle. In hindsight, it makes a lot of sense to place this chapter right after the previous one which required lots of actual calculation. More of the same, but easier since the problems are practical. I scored 21/26 on the exam and got at least partial credit on each problem. My previous study helped, but it wasn't a walk in the park either.
Chapter 11 - The pin is another chapter on tactics. I found this one slightly harder than the previous tactics lessons, but not particularly hard if you've done serious tactics training before. I only bothered setting up 2 of the positions on the board as I was able to spot the right idea quickly from the diagram and work through the variations. I scored 19/21 on the chapter exam, missing only 1 question which had a pretty idea I'd never seen elsewhere. Not surprising, this one was a composition and not from an actual game. Practical nonetheless.
Chapter 12 - The double attack is the 6th chapter on tactics. I consider this one easier than the chapter on pins. A couple of the examples are from compositions, but all of the exercises are from actual games. I did all but 1 of the chapter exercises from my head and didn't need more than 5 minutes for them. At least 4 of the exercises I've seen elsewhere. I scored 15/17 missing 1 question. It was odd because it was a problem I've seen before in Ivaschenko 1b (I think). Something in the back of my mind was telling me that there was a flaw with the obvious solution. Then I noticed that the end of my variation was losing, so I modified that. Problem was, it was my first move that was the issue. I know I made that same mistake previously when training the problem before.
It's the halfway point of book 1!
Some quick stats on the book and my performance this far:
The book is 6/12 tactics, 2/12 endgame, 1/12 calculating variations, 1/12 strategy, 1/12 positional play, 1/12 openings. Heavy on tactics, with a little bit of everything else sprinkled in. Looks like the training you'd get doing lots of tactics and reading annotated master games to cover the other stuff which is what I've been recommending to others.
I've been keeping track of my scores in a spreadsheet (of course!) and have been rating the chapter exercises as gold (excellent), silver (good), bronze (pass) and red (fail).
Yusupov recommends redoing any chapters you failed and I've kept up with that recommendation, going so far as to do it a 3rd time a few days after to make sure I still have it down. Amateurs practice until they get it right, experts practice until they can't get it wrong.
Chapter 13 - Realizing a material advantage is the 2nd on positional play. The main ideas are how to force favorable trades into a simple winning endgame by attacking with your extra material. Also a good lesson on giving some of the material back to simplify and stop counterplay. Almost all of the exercises here come from Yusupov's own games. Two of the exercises are from a Capablanca game I've seen before although I don't recall exactly which annotated games collection I read it from. I managed 12/22 points, which was good enough for a pass.
I'm getting through this book much quicker than I thought, although I'm not rushing. The chapters I had trouble with take me 2-3 hours to complete, but most I'm able to complete in an hour or less. I really like how he mixes up the objective from chapter to chapter which keeps the lessons from feeling repetitive. It's also nice that I'm able to regain some motivation after a tough chapter with an easier one on endgames or tactics.