Chess Opening Theory/1. e4/1...c5/2. Nf3/2...Nc6/3. d4/3...cxd4/4. Nxd4/4...Nf6/5. Nc3/5...e5/6. Ndb5

= Sveshnikov Sicilian = Moves:1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5

The White knight's threat of check on d6 is a bit awkward: ...Ke7 would be unpleasant so Black would have to surrender his bishop with ...Bxd6, only to have a queen arrive on d6 and single-handedly cramp the whole Black position. She would need to go, too: ...Qe7 Qxe7 Kxe7/Nxe7, and suddenly Black's dodgy d-pawn and slow development are significant factors in the much simplified position. Far better to keep the knight out of d6 for now and then vanquish it to a3 in a move's time with 6...d6.

Theory table
1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5