The Siberian trap is lesson 8 of 10 in Brilliant sacrifices 1: classic traps, an opening course suited to players rated around 900 (beginners). Smith-Morra Gambit, B21. Black offers a knight on d4 to mate on h2. It has 3 interactive exercises: 3 find-the-move puzzles. You play every move on a board and get feedback straight away. The lesson is free.
What this lesson explains
This is the Smith-Morra Gambit. Your knight on g4 and queen on c7 both aim at h2. White just kicked the knight with h3. Do not retreat it. About 9,148 rated games on Lichess have reached this position.
Nd4! The knight attacks White's queen. And if the knight on f3 takes it, Qh2 is mate.
After Nxd4, Qh2 is checkmate. The white knight that stood on f3 guarded h2, and now it is gone.
Recap.
In the Siberian, the queen on c7 and the knight on g4 aim at h2.
After h3, Nd4 hits the queen.
Nxd4 allows Qh2 mate.
So White loses the queen.
What you practise
First play the line. You are Black: play the moves of the Smith-Morra Gambit, up to the moment of the sacrifice.
Your turn: find the sacrifice. You are Black. White attacked your knight with h3. Use the other knight to hit the queen.
White sees the mate and takes on g4 with the h-pawn. Now take the queen with check.
Worked examples
First play the line. You are Black: play the moves of the Smith-Morra Gambit, up to the moment of the sacrifice. Good. White answers h3. Now the position is ready for the sacrifice.
Your turn: find the sacrifice. You are Black. White attacked your knight with h3. Use the other knight to hit the queen. That is the Siberian trap. White cannot take on d4 because of Qh2 mate, so the queen is lost.
chessGM