Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...Nge7

Cozio defence C60 Spanish game 3...Nge7 · Cozio defence The Cozio defence is an unusual but sound sideline that can be used to avoid main line Spanish theory. On e7, Black's knight prevents the development of their king's bishop. Black has two ways to resolve this: one plan is to move the knight again, ...Ng6, the other is to play ...g6 & ...Bg7. The latter option resembles the fianchetto defence, 3...g6. The immediate utility of 3...Nge7 is that it prepares to recapture on c6 with a knight, Bxc6? Nxc6!, so Black avoids doubling their pawns or dropping e5. After 4. O-O, the modern main move, Black makes a decision as to their bishop. If Black wants to keep the deterrent of Bxc6? Nxc6!, then they will need to play with 4...g6 and the kingside fianchetto. Otherwise, the line is 4...Ng6, from where the knight defends e5 and the trade on c6 is no longer so useful for White anyway. 4. Nc3, uncommon in the Spanish, is the main sideline, where 4...g6 is the Paulsen variation. There there is 5. d4! exd4, and White's idea is not to recapture immediately but to play 6. Nd5. 6...Bg7 7. Bg5! h6 8. Bf6 Bxf6 9. Nxf6+ Kf8+. 4. c3 was one of the main approaches in the 19th century, as recommended by Carl Jaenisch over 4. d4 in 1848, writing that it "affords Black no satisfactory method of developing his game."Carl Jaenisch 1848 Major Jaenisch On Ruy Lopez' Knight's Game Chess Player's Chronicle 9 219 https://www.google.ch/books/edition/The_chess_player_s_chronicle/ja5AAAAAcAAJ?hl=en&gbpv=1&pg=PA216 10 December 2025 In 1865, Zukertort scored a win over Anderssen in a twelve move miniature with 4. c3 d6 5. d4 Bd7 6. O-O Ng6 7. Ng5 h6 8. Nxf7 Kxf7 9. Bc4+ Ke7?? (9...Ke8 is better, so that 10. Qh5 can be met with ...Qf6) 10. Qh5 Qe8?? (better was to give up the knight) 11. Qg5+ hxg5 12. Bxg5# 1-0Zukertort v Anderssen, 1865. Chessgames.com 4. d4 is also playable. History 1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. c3 d6 5. d4 Bd7 6. O-O Ng6 7. Ng5 h6 8. Nxf7 Kxf7 9. Bc4+ Ke7?? 10. Qh5 Qe8 11. Qg5+ hxg5 12. Bxg5# Final position from Zukertort v Anderssen, 1865. left 1 Named for Carlo Cozio, 18th century Italian chess master. The line was popular in the 19th century but became unfashionable by the 20th in favour of 3...a6 and 3...Nf6. It is recommended occasionally as a non-theoretical reply to 3. Bb5: an "Anti-Spanish".Anti-Spanish. The Cozio Defence Dreev Alexey Chess Stars Ltd 2014 978 619 718801-1 Sofia Levon Aronian helped to re-popularise it in 2009, playing it exclusively with black against 3...Bb5 in the 2009 World Blitz Championship.Levon Aronian's games under C60. Chessgames.com Theory table References See also Ruy Lopez External links "1.e4 e5 Club Player's Dynamite", GM Simon William's Chessable course on the Cozio.