1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5!
A very interesting move which can transpose in many variations of the Pirc defence.
4...Bg7
The most logical move ! But : 4...c6 should transpose in one of the other variations. as well as 4...h6.
5.f4!?
The "normal" move is 5.Qd2, nevertheless with 5.f4 white avoids the h6, g5 and Nh5 plan.
5...c6
5...h6 6.Bh4 c5 7.dxc5 Qa5! Threatening Nxe4 8.Qd2 Qxc5 9.Bd3 Nc6 10.Nge2 0-0 11.0-0-0 All the other alternatives give black a very confortable game, white must head for a complicated and asharp middlegame. The only game we have for this variation is the game Yermolinsky-Gulko 1996. 11...Nb4 (11...b5 12.Bxf6 Bxf6 13.Nd5 Be6 14.Nxf6+ exf6 15.Kb1 With an advantage to white according to Yermolinsky.) 12.Kb1 Be6 13.Rhf1 Qa5 14.a3 Nxd3 15.cxd3 Rfc8 16.h3 With good attacking chances
5...c5 6.dxc5 Qa5 White should simply play as in the h6 variation. 7.Bd3 Qxc5 8.Qd2 Nc6 9.0-0-0 0-0 with good attacking chances, see 5...h6 6.Bh4 c5.
5...0-0 6.Qd2 c5 (6...c6 is a transposition to the main variation.) 7.dxc5 dxc5 8.0-0-0 Qxd2+ 9.Rxd2 Nc6 10.Bc4 h6 11.Bh4 Nh5 12.g3 += as in Antonio-Markowski
6.Qd2!
The main line of the Bg5 variation, nevertheless with a different move order black could have played : 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 Bg4 5.Qd2 h6 6.Bh4 g5 ! 7.Bg3 Nh5 with an unclear position.
6...b5 7.Bd3 0-0 8.Nf3 Bg4!
In this kind of positions g4 is a very good square for the black bishop.
[8...Nbd7?! 9.e5 b4 10.Ne2 Nd5 11.exd6 f6 12.dxe7 Qxe7 13.Bh4 N7b6!? (13...Ne3? as in Krays-Beim 14.Bf2+-) 14.0-0 I don't think that black has enough compensations for the pawn, the game Loefller-Bernard ended in a draw. 14...Bh6 15.Ne5 Qd6 16.Nc4 Nxc4 17.Bxc4±
8...b4?! 9.Ne2 Qb6 (9...a5? is very ugly, don't forget to develop your pieces.) 10.f5 Gave white the attack in Gofshtein-Kulaots 10...e5?! (10...gxf5 11.exf5 c5 12.Bh6 Bxh6 13.Qxh6 Nc6 14.Ng5 Nxd4 15.Ng3+- is an example of how white should play the attack
9.0-0!?
Let me explain why I prefer this move in comparison to 9.e5 for example. After 9.0-0 the white rook occupies the f file and the white king will soon be in security at h1.
9...Qb6 10.Ne2
More or less forced
10...Nbd7 11.Kh1!
Of course !
11...d5!
11...Rae8 12.a4! b4? This move was played in Alexandrov-Savicevic but I dont like it as white can play : (12...d5!? 13.Bxf6 Nxf6 14.e5 Ne4 15.Qe3 f6 16.h3 Bc8 17.axb5 cxb5 18.Bxe4 dxe4 19.Qxe4 Bf5 20.Qd5+ and white keeps the advantage) 13.c4 bxc3 14.bxc3 d5 15.Ng3 With a great advantage
11...b4? This move shows a very bad understanding of the position, as it allows the thematic : 12.c4! += as in Kutuzovic-Feletar.
12.Bxf6 Nxf6
The only interesting move :
12...exf6?! was played in Smirin-Beim but after 13.exd5 cxd5 14.f5 white has the advantage
12...Bxf6 13.e5 Bg7 14.f5 Bxf5 15.Bxf5 gxf5 16.Ng3 e6 17.Nh5 In my opinion this variation gives white very good attacking chances.
13.e5 Ne4 14.Qe3 f6
According to John Nunn in The Ultimate Pirc, I quote : "This position would have been unclear", but he does not analyze the simple :
[Just a few words on : 14...Bf5 15.Nh4 f6? 16.Nxf5 gxf5 17.e6 as in Seres-Zimmerman]
15.h3 Bf5 16.g4 Be6!
16...Bd7 17.Bxe4 dxe4 18.Nd2 f5 19.gxf5 gxf5 20.Rg1±
17.exf6 exf6 18.Nh4 f5 19.gxf5 gxf5 20.Rg1 Rae8 21.Rg2 Bd7 22.Rag1 Rf7 23.Qf3±
And in my opinion white has the better position, he occupies the only open file and black bishop paire is somehow powerless.