Kieseritzky Variation

The Kieseritzky Variation answers the exchange on d4 with 3. Nf3 rather than the immediate 3. Qxd4. Instead of bringing the queen out early, where ...Nc6 can chase it, White develops a knight that also attacks the d4-pawn, intending to win it back with Nxd4. Delaying the recapture in this way resembles the Scandinavian line 1. e4 d5 2. exd5 Nf6. The cost is that Black stays a pawn up for the moment and chooses the character of the game. The engine assesses the position as roughly balanced.

Most games transpose to other openings. In Lichess games the most frequent replies are 3...d6, which reaches the Exchange Variation of the Philidor Defense, and 3...Nc6, which gives the Scotch Game, usually reached by 1. e4 e5 2. Nf3 Nc6 3. d4 exd4. A third option, 3...Nf6, leads to the Modern Attack of Petrov's Defense. The developing move 3...Bc5 can also return to familiar ground, since 4. Nxd4 Nc6 is a Classical Scotch. After 4. c3, however, White plays the Lanc-Arnold Gambit and offers a pawn. Alekhine recommended 3...Bc5 4. Nxd4 Nf6, meeting 5. e5 with 5...Qe7. The engine prefers the check 3...Bb4+, with 3...Bc5 and 3...Nc6 close behind.

The main independent try is 3...c5, which supports d4 and tries to keep the extra pawn. Some sources reserve the name Kieseritzky Variation for 3...c5 4. Bc4 b5. Black accepts a loosened queenside and slower development in exchange for the material, and White aims at f7 and the open central files. In practice White scores well against 3...c5. The counterstrike 3...d5 is rare, and results after it are close to even.

The line is named after Lionel Kieseritzky, who used it in a blindfold simultaneous exhibition in 1851 against Henry Witcomb and later published his annotations in La Régence, the journal he edited. That game went 3...c5 4. Bc4 d6 5. Ng5 Nh6, with White's knight and bishop bearing down on f7 and Black's knight covering it. The position is reached fairly often in online play, and White scores somewhat better than Black there.