Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...Bc5/4. c3/4...d5

4...d5?! is the Konikowski gambit. Black strikes in the centre. By moving their d-pawn, Black pins their own knight. Thus, Black offers white their choice of central pawns to capture, d5 or e5.

If 5. exd5, Black can recapture 5...Qxd5, taking advantage of the fact that, having played c3, White has taken away that square from their knight and so cannot gain tempo on the queen with Nc3. From this position, Black threatens Bxf2+ with a discovered attack on White's bishop.

6. d4 is playable (though after 6...exd4 7. cxd4?? is a mistake, allowing 7...Bb4+ to win the knight). 6. O-O allows Bxf2+ 7. Rxf2 Qxb5 and Black is up a pawn.

The best continuation however is 6. Qe2, defending the bishop and pinning the e-pawn, threatening to take on e5 with check, e.g. 6...Be6 7. Qxe5 Qxe5+ 8. Nxe5 and White is up a pawn.

5. Nxe5 captures the e5 pawn that Black undefended when they played 4...d5?! and pinned their own knight. This threatens to take the pinned knight and win a pawn (Nxc6 bxc6 Bxc6+).

Black's tricky move 5...Qf6? appears to threaten both White's knight and Qxf2#, and if 6. Nf3? dxe4 recovers the pawn at least. However White has 6. d4, both defending the knight and interposing between the bishop and the f2 square.

A better try for Black is 5...Qg5, forking the knight and the g2 pawn. If 6. Nxc6 Qxg2, Black threatens Qxh1# and Qxe4+. Instead, the best continuation for White is to give up on the knight, knowing that they can recover a bishop by forking on d4: 6. O-O Qxe5 7. d4 Qe6 8. dxc5.

5. d4? offers a countergambit. If 5...dxe4? then 6. Nxe5 is winning. There is no 6...Qg5 in this position because 5. d4 opened up White's queenside bishop, so White is simply going to be up a pawn and the exchange after 6...Bb6 (e.g.) 7. Nxc6 bxc6 8. Bxc6+ Bd7 9. Bxa8 Qxa8.

However, if 5...exd4 then the position is equal.

Declining the gambit with e.g. 5. Qe2 or 5. O-O is also fine for White and avoids the sharper lines.

The Konikowski gambit is named for Jerzy Konikowski (1947-), Polish-German FM, who played it with some success in the 1960s and 1970s. It is also called the Konikowski-Hardy Gambit for Konikowski and Otto Henry Hardy (1927-2010^[1]).

For explanation of theory tables, see theory table and for notation, see algebraic notation.

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