King's English Variation, Two Knights Variation

The Two Knights Variation (ECO A22) arises after 1. c4 e5 2. Nc3 Nf6 and is the most popular reply to the Reversed Sicilian. Black brings the king's knight out at once and keeps two plans in reserve: a central strike with ...d5, or development of the dark-squared bishop, frequently to b4 against the c3-knight. Unlike 2...Nc6, the move leaves the e5-pawn without a defender for the moment, so White's choice on move three largely determines the character of the game.

The most common choice is 3. g3, the Carls-Bremen System. White puts the bishop on g2 before deciding where the king's knight belongs, which strengthens the hold on d5 and adds long-diagonal pressure on Black's queenside. Four Black replies carry their own names. 3...d5 is the Reversed Dragon, in which Black occupies the center and accepts a Dragon-type structure with colors reversed if White exchanges on d5. 3...Bb4 is the Smyslov System, targeting the c3-knight before White can complete development. 3...c6, the Keres Variation (A23), prepares a compact pawn chain that blunts the g2-bishop and obliges White to break it up with pawn advances. 3...g6, the Fianchetto Line (A24), mirrors White's kingside setup.

The second main move, 3. Nf3, attacks e5 directly, and Black usually covers it with 3...Nc6, entering the Four Knights Variation. White then normally fianchettoes and castles short, while Black's characteristic resource is the pin ...Bb4, combining the threat to double White's c-pawns with the possibility of pushing the e-pawn to gain space. Less often White plays 3. e4, fixing a central pawn early, and 3. f4, the Mazedonisch, is a rare attempt to challenge e5 immediately.

Play is generally maneuvering rather than forcing, and much depends on transpositions between the fianchetto and Four Knights complexes. The engine regards the position as roughly balanced, with Nf3, d3 and g3 as its preferred moves. In practice White scores somewhat better, winning a little over half the games against about 44% for Black, with draws uncommon.