Kangaroo Defense: Keres Defense, Transpositional Variation

The Kangaroo Defense: Keres Defense, Transpositional Variation is a chess opening characterized by an early bishop check and a flexible pawn structure.

The opening is a solid and flexible defense for Black, which can lead to various pawn structures and middlegame plans. It starts with Black playing an early Bb4+ to disrupt White's plans and force them to block the check with their knight. This move can be a bit provocative, as it invites White to gain a tempo by attacking the bishop later with a pawn.

The main idea behind this opening is to create a flexible pawn structure for Black, allowing them to choose between different pawn breaks and setups depending on how White proceeds. One of the key features of this opening is that it can easily transpose into other openings, such as the Nimzo-Indian Defense or the Bogo-Indian Defense, depending on the moves played by both sides.

This opening is named after the Estonian Grandmaster Paul Keres, who was one of the strongest players in the world during the mid-20th century and used this defense with great success. The transpositional nature of this variation makes it a tricky weapon for Black, as it can catch White off guard and lead to positions they may not be familiar with.

While not as popular as some other defenses against 1.d4, the Kangaroo Defense: Keres Defense, Transpositional Variation remains a viable and interesting option for Black players looking for a flexible and somewhat offbeat opening choice.