Closed, Chigorin Defense

Mikhail Chigorin developed 9...Na5 in the years around 1900, and for over half a century it served as Black's main answer in the classical Closed Ruy Lopez (Spanish Game). The knight move evicts the bishop from the a2–g8 diagonal and clears the c-pawn's path, so Black can expand on the queenside with ...c5. Almost every game continues 10. Bc2. The classical sequence is then 10...c5 11. d4 Qc7, where the queen protects e5 and waits on the c-file in case ...cxd4 opens it. Black also has 11...Bb7 and 11...Nd7, the second of which Paul Keres used in the 1960s. If White permits it, Black often reroutes the knight with ...Nc6 and keeps extra room on the queenside.

The Panov System, 12. Nbd2 cxd4 13. cxd4, settles the central tension early. The Gajewski Gambit, 10. Bc2 d5, gives up the e-pawn so that Black can open the position. It is objectively less reliable than 10...c5 but awkward to face over the board. The line lost ground because the knight on a5 takes time to rejoin play, and the Breyer and Zaitsev Variations largely replaced it. Engines give White a slight edge.