It is of particular theoretical importance as a way for Black to play actively and avoid the so-called "Spanish Torture" of the Closed Ruy Lopez.

[5] Since its debut, many top players have adopted the opening and further developed its theory, notably Boris Spassky in his 1965 match against Mikhail Tal.

White also suffers from an under-developed queenside and faces some difficulties developing its remaining knight since the pawn on c3 blocks one of its squares.

However, White may reach an endgame with a pawn advantage if able to withstand Black's attack.

For many years, 8. a4 was the most common owing to Garry Kasparov's victory over Nigel Short in the 1993 World Chess Championship.