It's so nice to see something different. These days the chess publishing formula seems to be 75% opening manuals, 10% endgame guides, 10% game collections and odds and ends, and 5% experimental books like Rowson's fantastic The Seven Deadly Chess Sins. Kosikov's Elements of Chess Strategy falls into this all too marginal category. Elements is a guide for forming a chess plan in the Jeremy Silman (How to Reassess Your Chess) or Jonathan Tisdall (Improve Your Chess Now!) vein. Kosikov strikes a nice balance between overall planning advice and useful strategy nuggets on topics like passed pawns or the principle of two weaknesses.
One thing that I especially like is that Kosikov's guide is very practical. Starting on page 109, for example, he discusses the concept of "serial errors." Since I'm writing this review a day after being in this situation I found it especially relevant. How many times have we missed an opponent's saving idea only to make a mistake moments later that allows equality and then a further mistake that costs us the game. The tables can turn so quickly in chess! But Kosikov reminds us: "don't castigate yourself!" and "start again from the beginning!" It's nice to see a middlegame planning theorist who can write as though he's actually played a tournament game before.
I also want to mention the exercises in the book which are plentiful, well thought out, and feature nice explanatory answers. Now I'm a lazy reader so I found myself skipping straight to the solutions (misses the point I suppose), but if you're looking to improve, this is going to be great. I enjoyed them if only because I was a glutton for the kinds of problems presented in Silman's How to Reassess Your Chess Workbook and the problems here are very similar.
Despite my perpetual delusion that the newest opening manual will finally get me my master title, I've only ever used two kinds of chess books to improve: tactics manuals and middlegame planning books. Kosikov's book falls into the latter category, so check it out!