3...Nf6 4.d4 Nxe4 5.d5: Jaenisch main line is variation 1 of 6 in the Ponziani Opening course, a beginner opening course for White (ECO C44). It runs 19 moves and begins 1. e4 e5 2. Nf3 Nc6 3. c3 Nf6 4. d4 Nxe4 …. Black grabs the e4 pawn. White gains space with 5.d5 and wins the pawn back on e5. After the knight trade White pins the e4 knight on the e-file and keeps more space. In the lesson every move is explained on a board and then drilled; it is free.
Move by move
1. e4 – White takes the centre and opens lines for the queen and the f1 bishop.
1... e5 – Black claims an equal share of the centre.
2. Nf3 – White develops and attacks the e5 pawn.
2... Nc6 – Black defends e5 and develops a knight.
3. c3 – The Ponziani. The c3 pawn prepares d4 for a big pawn centre.
3... Nf6 – The Jaenisch Counterattack, Black's most common answer. The knight attacks e4.
4. d4 – White strikes in the centre at once. The e4 pawn is left alone on purpose.
4... Nxe4 – Black grabs the e4 pawn.
5. d5 – White gains space and chases the c6 knight.
5... Ne7 – The most common retreat. The knight heads for g6.
6. Nxe5 – White wins the pawn back. The knight stands well on e5.
6... Ng6 – Black challenges the e5 knight.
7. Nxg6 – White trades knights.
7... hxg6 – Black takes back. The h-file opens for the h8 rook.
8. Qe2 – The queen pins the e4 knight to the black king.
8... Qe7 – Black unpins and protects the knight.
The lesson goes on for 3 more moves, each with its explanation.
chessGM