Introduction
Grabinsky is becoming one of my favorite authors, despite having written only a handful of books. Being a world-class chess coach, his chess books carry his incredible teaching style and you can tell that he knows how people learn chess, what they struggle with, and what it takes for chess players to improve. That is very visible in Turbo-Charge Your Tactics. The two volumes are the works of Grabinsky, and his very successful student, GM Mykhaylo Oleksiyenko. Volume 1 consists of 270 problems. Each problem is unique, instructive, you may even say weird, as an emphasis seems to have been put on beauty and uniqueness of positions. The annotations are well written and they explain the core ideas for each position well. The workbook is suited for anyone below 1800 FIDE. Unlike the second volume, which provides positions from the games of the very best players, volume 1 comes with a wide range of players, games, and positions, including lichess puzzles and games from online play. In any case, Turbo-Charge Your Tactics is a great chess puzzle book for improving players.
About the Authors

Grabinsky is an IM, and more known for his works and coaching. He is the coach of the Ukrainian youth team and has had astonishing success throughout his career with many of his students becoming Grandmasters; Andrei Volokitin, the co-author of Perfect your Chess, Yuriy Kryvoruchko, Martyn Kravtsiv, the author of 400 Chess Strategy Puzzles, Yaroslav Zherebukh, Yuri Vovk, Andrey Vovk, Mikhailo Oleksienko, who has co-authored Turbo-Charge Your Tactics with Grabinsky, Nataliya Buksa, Vita Kryvoruchko, Myroslava Hrabinska and Kateryna Matseyko.
Mykhaylo Oleksiyenko is one of Grabinsky’s famous students. He became a Grandmaster at the age of 19 and has had many tournament successes. Oleksiyenko won in clear first in the Summer Olomouc Open in 2005, Breizh Masters tournament in 2006 and 2007, and Instalplast Open in 2006, and in 2015 he won the Karen Asrian Memorial in Jermuk. He also holds a Ph.D. in mathematics.
Problem Difficulty
Unlike Perfect Your Chess, in which Grabinsky assembled a collection of master-level problems, both volumes of Turbo-Charge Your Tactics are aimed at players who haven’t reached advanced level yet. They are divided not by theme or tactical motif, but by who was playing the game.
Personally, I don’t see much point to that structure, but there it is. I also don’t think that the difficulty increases as you progress through the chapters, at least not significantly, which is the case for many puzzle books, such as Aagaard’s GM Preparation series.

Quality of Annotations
The annotations are perfect. As is the case with his next book, Grabinsky managed to explain things on a level useful for masters but understandable for lower rated players as well. That is what I like most about the book.
A single line and a unique solution is given for most problems, with a few sidelines thrown in here and there but without infinite branching. I would say that the two volumes of Turbo-Charge Your Tactics can be solved without a board by anyone above 1800 FIDE. The annotations are extensive, and the variations easy to follow, making this a perfect “bus book”, my term for depicting books that you can take on a trip and know you can learn from without having to have a board set up next to you. For lower rated players, following without a board will be difficult, so use a board.

Conclusion
Turbo-Charge Your Tactics is a great resource for improving players. Despite having been written by a coach who managed to train a dozen players to GM level, and one of his most successful students, it’s aimed for intermediate level improvers who’ve mastered the basics of tactical play and are looking to expand their library of tactical patterns and motifs, to develop their calculation and visualization skills, and, most importantly, become better at creative problem solving over the board.