C66 Ruy Lopez: Berlin Defense, Improved Steinitz Defense
C66 holds seven named lines, all under the name Ruy Lopez. It leaves C65 (Ruy Lopez: Berlin Defense) with 4...d6. Material is no longer level at the end of two of its lines; the widest gap, three pawns in White’s favour, comes in Ruy Lopez: Berlin Defense, Closed Showalter Variation. That final move, by the d-pawn, covers c5 and e5 and opens a line for the bishop on c8 and the queen on d8.
| # | White | Black |
|---|---|---|
| 1 | e4 | e5 |
| 2 | Nf3 | Nc6 |
| 3 | Bb5 | Nf6 |
| 4 | O-O | d6 |
Lines filed under C66
All seven share the start 1.e4 e5 2.Nf3 Nc6 3.Bb5 and then split two ways at Black’s move 3.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| Ruy Lopez: Berlin Defense, Improved Steinitz Defense | 3...Nf6 4.O-O d6 | 8 | White castled |
| Ruy Lopez: Closed Berlin Defense, Chigorin Variation | 3...Nf6 4.O-O d6 5.d4 Nd7 | 10 | White castled |
| Ruy Lopez: Berlin Defense, Closed Wolf Variation | 3...Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 exd4 | 12 | Black +1, White castled |
| Ruy Lopez: Berlin Defense, Hedgehog Variation | 3...Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 | 12 | White castled |
| Ruy Lopez: Berlin Defense, Closed Bernstein Variation | 3...Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Bg5 | 13 | White castled |
| Ruy Lopez: Berlin Defense, Closed Showalter Variation | 3...Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Bxc6 | 13 | White +3, White castled |
| Ruy Lopez: Berlin Defense, Tarrasch Trap | 3...d6 4.d4 Bd7 5.Nc3 Nf6 6.O-O Be7 7.Re1 O-O | 14 | both castled |
The road to C66
- 1.e4 … 3.Bb5five earlier stops: B00, C20, C40, C44, C60
- 3...Nf6C65 Berlin Defense
- 4.O-OC65 Berlin Defense
- 4...d6C66
The position after 4...d6
White has brought out the knight on f3 and bishop on b5; Black the knight on c6 and knight on f6. White could capture with Bxc6+, Nxe5. White is to move and has 29 legal moves.
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| C79 | Ruy Lopez: Morphy Defense, Steinitz Deferred | four squares: a4, b5, a6, a7 |
| C62 | Ruy Lopez: Steinitz Defense | six squares: e1, f1, g1, h1, f6, g8 |
| C72 | Ruy Lopez: Morphy Defense, Modern Steinitz Defense | six squares: a4, b5, a6, f6, a7, g8 |
| C78 | Ruy Lopez: Morphy Defense | six squares: a4, b5, a6, d6, a7, d7 |
| C69 | Ruy Lopez: Exchange Variation, Normal Variation | seven squares: b5, a6, c6, d6, f6, a7, g8 |
| C48 | Four Knights Game: Spanish Variation | eight squares: b1, e1, f1, g1, h1, c3, d6, d7 |
| C55 | Italian Game: Two Knights Defense | eight squares: e1, f1, g1, h1, c4, b5, d6, d7 |