Classical Variation, Frankfurt Variation

The Frankfurt Variation branches from the Vistaneckis line, 5...Ng8. In that line Black retreats the knight to its home square so that it can recapture on e7 if White exchanges bishops. White declines the trade with 6. Be3, keeping the dark-squared bishop. Black answers 6...b6, which prepares to develop the light-squared bishop on the queenside rather than leave it behind the e6-pawn. The play is closed and maneuvering, built around the familiar French chain of d4–e5 against d5–e6.