Sämisch Variation

King's Indian Defense

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 Nh5

White plays f3 to build a broad pawn center and prepare a kingside attack, popular with aggressive players.

Fun fact: The Sämisch is named after Friedrich Sämisch, who developed the system in the 1920s. Source

The idea

White plays 5.f3, guarding e4 solidly and preparing Be3, Qd2 and often long castling followed by a kingside pawn storm with g4 and h4. In this line, 5...O-O 6.Be3 e5 7.d5 Nh5, the center is closed and Black's knight goes to h5 to prepare ...f5.

Plans for White

Play Qd2 and castle queenside, then g4 to push the knight on h5 away and attack with h4-h5. Alternatively, castle kingside and play on the queenside, as in other King's Indian lines.

Plans for Black

Use the knight on h5 to support ...f5, the main break. Black can also play ...Nd7 and ...a5, or open the queenside with ...c6 and ...b5 if White castles there.

Watch out for

For Black, the knight on h5. If ...f5 doesn't come in time, White's g4 kicks the knight away and it can end up stranded on the edge of the board.

For White, the dark squares. The pawn on f3 weakens g3 and e3 for a moment, and the king often stays in the center while White prepares its attack. Black's queen and bishop can use those squares if White is careless.