Kveinis Variation

The Kveinis Variation, also spelled Kveinys, arises when Black answers the Open Sicilian with the immediate 4...Qb6 instead of a developing move. The queen hits b2 and the knight on d4, and through it the f2-square. The usual follow-up is ...Bc5, which stacks attackers on d4 and f2, while ...Nc6 adds a third. The b2-pawn is generally poisoned, but capturing it leads to sharp play that can be hard for White to handle. The line is named after the Lithuanian International Master Aloyzas Kveinys, and Nigel Short and Judit Polgar have also used it.

The most common reply is 5. Nc3, which leads to sharp positions. After 5...Bc5 6. Be3 Nc6, the accurate 7. Na4 is needed, for example 7...Qa5+ 8. c3 Bxd4 9. Bxd4 Nxd4 10. Qxd4 e5. The natural 7. Nxc6? is a frequent error because of 7...Bxe3 8. fxe3 Qxe3+. The main line is 5. Nb3, which takes the knight out of range and covers c5 to prevent ...Bc5. 5. c3 also appears. The engine gives White a slight edge, but Black scores very well in Lichess games, and the line works well as a surprise in fast time controls.