Ruy Lopez: Morphy Defense, Cozio Defense

A solid and less common defense in the Ruy Lopez, this opening aims to develop the knight to a more passive square while maintaining flexibility.

The opening is characterized by the development of the black knight to e7 instead of the more common d6. This move allows Black to maintain flexibility in pawn structure and avoid some of the main lines of the Ruy Lopez. The defense is considered a solid, albeit passive, choice for Black, as it does not immediately challenge White's center.

In this opening, White typically continues with standard Ruy Lopez moves, such as c3 and d4, to build a strong pawn center. Black's plan often involves fianchettoing the light-squared bishop and potentially playing for d5 at an opportune moment. The knight on e7 can also be rerouted to g6, supporting the e5 pawn and potentially eyeing the f4 square.

While not as popular as other defenses in the Ruy Lopez, this defense has been employed by strong players, including former World Champion Anatoly Karpov. It can lead to rich and complex middlegames, with chances for both sides.

However, it is worth noting that this defense can be somewhat passive and may not suit the tastes of aggressive players. It requires patience and a deep understanding of the resulting pawn structures and piece coordination to be played effectively.