First let me explain the title of this post: I don't really do book reviews in my blog. And I especially don't do reviews of technical opening repertoire books. However, I have to make an exception when one of my friends has a new book published, a labor of love that they have been working on for the last five years.
So what I can say is this: Eric Montany's The Modern Sämisch is an excellent, very readable, very thoroughly researched book of a genre that I hardly ever read. The subject of his attention is the Sämisch (or Saemisch) Variation of the King's Idian Defense, where White plays 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3. More precisely, the entire book is about a sub-variation where Black plays 5. ... O-O (the automatic move) and White plays 6. Bg5 (the #2 variation, played 7137 times on ChessBase, compared to the main variation 6. Be3, which has been played 38,483 times).
Position after 6. Bg5. The tabiya for Eric's book.
FEN: rnbq1rk1/ppp1ppbp/3p1np1/6B1/2PPP3/2N2P2/PP4PP/R2QKBNR b KQ - 0 6
Why an entire 350-page book about a sub-variation? Several reasons. First, because Eric truly believes that 6. Bg5 is better than 6. Be3. This is an opening book of the only kind I believe is worth buying -- a book by a true connoisseur of the variation. I do not believe in opening books by grandmasters who churn them out by the dozens. Give me an opening book by a lesser master who plays the variation all the time and knows all of its ins and outs.
More importantly, Eric makes a good case why this move is better. One reason that the Saemisch main line fell out of fashion in the 1990s was that Black discovered the gambit 6. Be3 c5! 7. dc dc 8. Qxd8+ Rxd8 9. Bxc5 Nc6 10. Nd5 Nd7. Because Black got very good results out of this, White started to play calmer lines like 7. Ne2. But after 7. ... Nc6 8. d5 Ne5, says Eric, we reach a position where White "would rather have his bishop on g5."
So why not just put the bishop on g5 to start with? One of the points of 6. Be3 was to prevent ... c5. Since that isn't working, there is no point (or not as much) to developing on e3.
There are a couple other arguments in favor of 6. Bg5. One is that there is a strong possibility that it will provoke Black into playing 6. ... h6, or perhaps the same thing a move later (6. ... c5 7. d5 h6). In this case White's intention is to retreat to e3, going into "main line" stuff but with an important difference: Black has played the weakening move ... h6. Although White has wasted a tempo with Bg5-e3, Eric argues that Black has wasted two tempi with ... h6 and ... Kh7 (which will in many cases be forced, to defend the h-pawn).
Another argument, which I can attest to as a person who has often played the somewhat similar Averbakh Variation (the same position as above except with Be2 instead of f3), is that these variations strongly discourage Black's "normal" plan in the King's Indian, which begins with ... e5. In fact, in our basic position, 6. ... e5? right away would be terrible because of 7. de de 8. Qxd8+ Rxd8 9. Nd5. And even after 6. ... h6 7. Be3, Eric argues that 7. ... e5 is inferior for Black. He calls this the "Attempted Classical" Variation and starts out with this as Chapter 1. I will not go into any of the details, but this alone makes the variation very attractive for use against sub-2000 players, who seldom know any other plans for Black besides the classical ... e5, ... f5-f4, etc. If your opponent insists on attacking kingside, you'll love castling queenside and watching him put his own king into danger. Most sub-2000 players can probably get their money's worth just by reading chapter 1 of the book and skimming over the rest.
However, that would be a shame because "the rest" is where Eric has devoted 90 percent of the pages and 95 percent of his work. He wants to write a book that will be useful for masters, too. He explains very well and in intricate detail the nuances of lines like ... Nc6, ... c5 (which he considers best) and ... c6 and even ... a6 (the "Attempted Benko," the one line that has a slight positive score for Black -- 50.2% -- in ChessBase).
My only criticism of the book is that the detail is overwhelming and the nuances are in some cases too nuanced for a practical player to remember. But this isn't a fault with Eric's book, it's just the way that opening books are these days, especially the ones aimed at masters. It's one reason that I don't buy them. Maybe I shouldn't say this, but it was sometimes even too much for Eric to remember. When we were going over some variations with Gjon Feinstein, sometimes Eric would have to consult his own book to remember what he (or in some cases his computer) had recommended.
One other positive feature of Eric's book is that he has chosen to organize it around thematic master games. I completely endorse this approach; there is nothing more frustrating than an opening book that evaluates a position "+/=" but doesn't tell you why. Eric not only tells you why, he gives you the complete source games. If nothing else, you can treat his book as a collection of 46 high-level master games with detailed analysis, all coming out of the basic position, and there is no question that simply by playing over the games you will learn a lot. The book may be worth your money as a games collection even if the Saemisch variation isn't your thing.