Lesson
White to move. Main line: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 Bc5 5. Nxf7 Bxf2+ 6. Kxf2 Nxe4+ 7. Kg1 Qh4
After 6...Nxe4+ the king has no good square: 7.Kg1 runs into 7...Qh4 with Qf2+/Qxg5 threats crashing through (8.g3 Nxg3! and the attack plays itself); 7.Ke3 is the computer’s ice-cold defense and survives — for an engine.
The deep idea: Black meets a threat against f7 not by defending but by creating a bigger one against f2. Both f-pawns are the weakest points on the board, and the Traxler is the purest demonstration that attacking speed can outweigh material.
Practical verdict: 5.Nxf7 loses over the board to anyone who knows the follow-up; 5.Bxf7+ is the move to learn as White. As Black, the Traxler is a weapon that turns a defensive-looking opening into a king hunt.
The critical test: 5.Bxf7+: 5. Bxf7+ Ke7 6. Bd5 — theory’s main line: White keeps material with the bishop check instead of the knight fork, and the game stays roughly balanced but sharp.