Berlin Defense

The Berlin Defense, 2...Nf6, answers the Bishop's Opening with an immediate counterattack on e4. It also covers h5, which rules out early Qh5 ideas against f7. It is Black's most popular second move. The game's direction depends almost entirely on how White deals with the attacked pawn, since each method leads toward a different opening: the Italian Game, the Vienna, Petrov's Defense or a Scotch Gambit type of position. The engine regards the position as roughly balanced.

The main line is 3. d3, the most frequent reply. It protects e4 for good and opens the diagonal of the queen's bishop. Black can steer for familiar ground with 3...Nc6 4. Nf3 Bc5, the Giuoco Pianissimo. Alternatively 3...Bc5 often joins the same structures after a later ...Nc6, while 4. Nc3 in that line is the Spielmann Attack. The Paulsen Defense, 3...c6, is the most testing try because it refuses to transpose. Throughout these lines Black has to keep a delayed f4 by White in mind.

With 3. Nc3 the game becomes the Vienna Game: Stanley Variation. The knight's protection of e4 is only apparent. After 3...Nxe4 4. Nxe4? d5 5. Bd3 dxe4 6. Bxe4 f5 7. Bf3, the center fork trick leaves Black better. White does better to regain the pawn with 4. Qh5 Nd6 5. Qxe5+, reaching equality. Black usually avoids the queen sortie with 3...Nc6, after which 4. d3 allows 4...Na5 and the bishop pair. The reply 3. Nf3 permits a Petrov. After 3...Nxe4 4. Nc3 Nxc3 5. dxc3 comes the Boden-Kieseritzky Gambit, where White gets active piece play, while 3...Nc6 transposes to the Two Knights Defense.

The Ponziani Gambit, 3. d4, gives White the best results among the common replies. After 3...exd4 4. Nf3, the Urusov Gambit, Black may keep the extra pawn with 4...Nxe4 5. Qxd4 Nf6. The other option, 4...Nc6, reaches a position better known from the Scotch Gambit. Taking on e4 at once with 3...Nxe4 is considered a mistake, because 4. dxe5 gives White attacking chances against f7. The Greco Gambit, 3. f4, transposes to the Bishop's Gambit after 3...exf4, but 3...Nxe4 and 3...d5 are regarded as stronger answers. Defending with 3. f3 weakens the kingside and takes f3 from the knight, and Black scores well against it.

Gioachino Greco recorded the earliest games with 2...Nf6, including the 3. f4 line that bears his name. For a long time the move was rated below 2...Bc5, until Carl Jaenisch argued in 1842 that it was Black's strongest reply. Von der Lasa gave it the name Berlin Defense (Berliner Partie) in his Handbuch des Schachspiels and credited it to the Berlin player Ludwig Bledow.