Sicilian Defense: O'Kelly Variation, Normal System, Cortlever Gambit

A sharp and aggressive chess opening that aims to create imbalances and tactical opportunities for both sides.

The opening is characterized by an early pawn push to a6 by Black, followed by a pawn exchange in the center and the development of White's light-squared bishop to c4. This gambit is named after the Dutch International Master Nicolaas Cortlever, who was known for his aggressive and imaginative play.

In this variation, Black aims to create counterplay on the queenside and in the center, while White seeks to exploit the weaknesses in Black's pawn structure and develop a strong initiative. The pawn on a6 can be useful for Black in supporting a later b5 pawn break, which can help to undermine White's central pawn majority and create counterplay.

White's light-squared bishop on c4 is well-placed to target the potentially weak f7 square in Black's position, and can also support a later pawn push to e5, which can help to open up the position and create attacking chances.

Both sides need to be well-prepared in this opening, as the resulting positions can be highly tactical and require accurate play. The Cortlever Gambit can lead to exciting and double-edged battles, making it an attractive choice for players who enjoy sharp and complex middlegames.

However, it is worth noting that this gambit is not as popular or well-established as some other lines in the Sicilian Defense, and players may find themselves in less familiar territory. This can be both an advantage and a disadvantage, depending on one's level of preparation and comfort with the resulting positions.