C71 Ruy Lopez: Morphy Defense, Modern Steinitz Defense
C71 holds four named lines, all under the name Ruy Lopez. It leaves C70 (Ruy Lopez: Morphy Defense) with 4.Ba4 d6. 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. Of all other reference positions, the board of C74 (Morphy Defense, Modern Steinitz Defense) comes closest, two squares apart.
| # | White | Black |
|---|---|---|
| 1 | e4 | e5 |
| 2 | Nf3 | Nc6 |
| 3 | Bb5 | a6 |
| 4 | Ba4 | d6 |
Lines filed under C71
All four share the start 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 and then split two ways at Black’s move 4.
| Name | After the shared start | Plies |
|---|---|---|
| Ruy Lopez: Morphy Defense, Modern Steinitz Defense | 4...d6 | 8 |
| Ruy Lopez: Morphy Defense, Modern Steinitz Defense | 4...d6 5.Nc3 | 9 |
| Ruy Lopez: Morphy Defense, Modern Steinitz Defense | 4...d6 5.c4 | 9 |
| Ruy Lopez: Noah’s Ark Trap | 4...b5 5.Bb3 d6 6.d4 Nxd4 7.Nxd4 exd4 8.Qxd4 c5 | 16 |
Ruy Lopez: Morphy Defense, Modern Steinitz Defense
- 4...d6 The d-pawn advances to d6, covering c5 and e5, opening a line for the bishop on c8 and the queen on d8.
- 5.Nc3 The knight leaves b1 for c3, opening a line for the rook on a1, guarding the bishop on a4 and the pawn on e4.
Ruy Lopez: Morphy Defense, Modern Steinitz Defense
- 4...d6 The d-pawn advances to d6, covering c5 and e5, opening a line for the bishop on c8 and the queen on d8.
- 5.c4 The c-pawn advances two squares to c4, covering b5 and d5, opening a line for the queen on d1 and the bishop on a4.
Ruy Lopez: Noah’s Ark Trap
- 4...b5 The b-pawn advances two squares to b5, covering a4 and c4, opening a line for the bishop on c8, attacking the bishop on a4.
- 5.Bb3 The bishop goes from a4 to b3.
- 5...d6 The d-pawn advances to d6, covering c5 and e5, opening a line for the bishop on c8 and the queen on d8.
- 6.d4 The d-pawn advances two squares to d4, covering c5 and e5, opening a line for the bishop on c1 and the queen on d1.
- 6...Nxd4 The knight on c6 takes the pawn on d4, attacking the bishop on b3 and the knight on f3.
The road to C71
- 1.e4 … 2...Nc6four earlier stops: B00, C20, C40, C44
- 3.Bb5C60 Ruy Lopez
- 3...a6C70 Morphy Defense
- 4...d6C71
The position after 4...d6
White has brought out the knight on f3 and bishop on a4; Black the knight on c6. White could capture with Bxc6+, Nxe5. White is to move and has 27 legal moves.
Codes that branch off from C71
The reference lines of three other codes leave C71 from the position after 4...d6, each with its own moves.
| Code | Moves | Reference line |
|---|---|---|
| C72 | 5.O-O | Ruy Lopez: Morphy Defense, Modern Steinitz Defense |
| C73 | 5.Bxc6+ bxc6 6.d4 | Ruy Lopez: Morphy Defense, Modern Steinitz Defense |
| C74 | 5.c3 | Ruy Lopez: Morphy Defense, Modern Steinitz Defense |
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| C62 | Ruy Lopez: Steinitz Defense | four squares: a4, b5, a6, a7 |
| C68 | Ruy Lopez: Exchange Variation | four squares: a4, c6, d6, d7 |
| C75 | Ruy Lopez: Morphy Defense, Modern Steinitz Defense | four squares: c2, c3, d7, c8 |
| C41 | Philidor Defense | six squares: f1, a4, a6, c6, a7, b8 |
| C44 | King’s Knight Opening: Normal Variation | six squares: f1, a4, a6, d6, a7, d7 |
| C50 | Italian Game | six squares: a4, c4, a6, d6, a7, d7 |
| C60 | Ruy Lopez | six squares: a4, b5, a6, d6, a7, d7 |
Where lines continue from here
Nine named lines filed under other codes pass through the position after 4...d6. Besides the codes above, they belong to C75.