Kennedy Variation, Keres Attack

After 1. e4 Nc6 2. d4 e5 3. dxe5 Nxe5, the Keres Attack continues with 4. Nc3. The Paulsen Attack's 4. Nf3 invites the knight exchange on f3. This move instead develops a piece that also guards e4 and leaves the f-pawn free to advance against the centralized knight later. Pieces stay on the board, and the position is open, with half-open d- and e-files. White's e4 pawn is the only central pawn, so play turns on piece activity and pressure against that pawn. The engine gives White a slight edge, and White scores somewhat better in practice.

The most common reply is 4...Nf6, which develops and hits e4 at once. Next comes 4...Bb4, which pins the c3 knight and adds to the pressure on the same pawn. The quieter 4...d6 supports the knight on e5, and of the three main replies it gives Black the best practical results. The engine's top choice is 4...Bc5, which develops the bishop toward f2. It also rates the retreat 4...Nc6 and 4...d6 highly.