King's English Variation, Two Knights Variation, Smyslov System

The Smyslov System arises after 1. c4 e5 2. Nc3 Nf6 3. g3 Bb4. Black answers the Carls-Bremen fianchetto by developing the dark-squared bishop actively instead of striking with 3...d5 or building a chain with 3...c6. The bishop eyes the c3-knight, so an exchange on c3 can leave White with doubled c-pawns. The knight is the piece that supports d5 and e4, which makes it the main defender of the light squares White's fianchetto is meant to control. Black thus gets quick kingside development and an early decision about the minor pieces.

White most often ignores the bishop and continues 4. Bg2, which the engine also prefers, accepting the possibility of ...Bxc3 in return for development and long-diagonal pressure. The rarer 4. Nd5 moves the knight forward, attacks the bishop and avoids the doubled pawns, and White has scored well with it. 4. Qb3 also hits the bishop and adds protection to c3, though results with it have been slightly better for Black. The engine rates the position as roughly balanced. In practice White wins somewhat more often, and draws are rare.