If White wants to face an actual King's Indian Defence, then he will play 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 and now he can choose between 5.Nf3 (Main Line KID); 5.f3 (Saemisch Variation); 5.f4 (Four Pawns Attack), 5.g3 (Fianchetto Variation) or lesser known options. Black will react accordingly, usually with 5...0-0, 5...e5 or 5...c5.
The Pirc Defence follows 1.e4 d6 (1...Nf6 is an Alekhine Defence allowing 2.e5 which interrupts Black's KID set-up) 2.d4 Nf6 (Attacking e4) 3.Nc3 g6 followed by 4...Bg7. Because White has not used a tempo to play c2-c4, he reaches the crossroads on move four. The main choices are 4.f4/5.Nf3; 4.Nf3/5.Be2; 4.Bc4/5.Qe2; and 4.Be3/5.f3.
This last option is the 150 Attack, named for the British rating level (about 1800 Elo) where that choice was particularly popular. Nowadays everyone plays 4.Be3 and 5.f3. The move f2-f3 can be played at any point up to move 7. White's intentions are to follow with Qd2/0-0-0/g4/h4/h5/Bh6. Almost the exact same idea can be found in the Saemisch Variation of the King's Indian Defence, the English Attack of the Najdorf Sicilian Defence (though without the Bh6) and the Yugoslav Attack against the Dragon Sicilian Defence.
This game begins 1.d4 g6 2.e4 Bg7 (Modern Defence) 3.Nc3 d6 4.Be3 Nf6 (Pirc Defence) 5.f3 (If 5.Qd2 Ng4 although the line is not bad for White after 6.Bg5.) 5...0-0 (A major fork in the road. Black may delay castling to begin a queenside attack with 5...c6.)
Our game continued 6.Qd2 Nbd7 7.0-0-0 a6 (Planning a queenside expansion.) 8.g4 b5 9.h4 Bb7 (The bishop is not effective here.) 10.Bh6 Rc8 11.h5 c5 12.d5 Ne5. Now it occurs to me that I would love to have a knight on g3. This is a 3 0 blitz game and for a second I forgot about the chronic hole on c4 which Black could now use for the first time. I blundered with 13.Nce2? (13.Bxg7! is the correct way to reach the game continuation.) 13...a5 (Black also playing fast uses good strategy but bad tactics. 13...Nc4! attacks my queen while she is protecting my Bh6.) After 14.Bxg7 Kxg7 15.hxg6 fxg6 16.Qh6+ Kg8 17.Ng3 White's attack is much faster.
My Ruy Lopez Tactics covers 500 combinations and mates.
My Open Game Tactics covers 1.e4 e5 without Ruy Lopez.
My Sicilian Tactics 1.e4 c5 has 500 combinations and mates.
My French Tactics 1.e4 e6 has 500 combinations and mates.
My Caro-Kann Tactics 1.e4 c6 500 combinations and mates.
My Semi-Open Tactics 1.e4 misc 500 combinations and mates.
My Blackmar-Diemer Tactics 500 combinations and mates.
My Queens Gambit Tactics has 500 combinations and mates.
My Indian Tactics 1.d4 Nf6 2.c4 500 combinations and mates.
My English Tactics 1.c4 500 has combinations and checkmates.
Sawyer - lhj, ICC 3 0 Internet Chess Club, 31.08.2011 begins 1.d4 g6 2.e4 Bg7 3.Nc3 d6 4.Be3 Nf6 5.f3 0-0 6.Qd2 Nbd7 7.0-0-0 a6 8.g4 b5 9.h4 Bb7 10.Bh6 Rc8 11.h5 c5 12.d5 Ne5 13.Nce2 a5 14.Bxg7 Kxg7 15.hxg6 fxg6 16.Qh6+ Kg8 17.Ng3 c4 18.g5 Nh5 19.Nxh5 gxh5 20.Rxh5 Rf7 21.Bh3 Rg7
22.Be6+ Kf8 23.Rh4 c3 24.Rf4+ Nf7 25.Rxf7+ Black resigns 1-0
