B42 Sicilian Defence: Kan

After 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6, ECO code B42 covers the Kan Variation of the Sicilian Defence with 5.Bd3. Black's 4...a6 keeps e7, f6 and d6 flexible and stops a knight or bishop from using b5. White's 5.Bd3 places the bishop behind the e4-pawn, ready for c4 and a Maróczy-style bind or for attacking chances on the kingside. One sharp try for Black is 5...Bc5, which hits the d4-knight and forces 6.Nb3. Then 6...Be7 drops the bishop back, since the knight on b3 is further from the centre and less useful there.