C09 French Defense: Tarrasch Variation, Open System, Main Line
C09 holds two named lines, all under the name French Defense. It leaves C08 (French Defense: Tarrasch Variation, Open System) with 5.Ngf3 Nc6. White, to move in that position, has 28 legal moves, the second-lowest count of the 19 French Defense codes. At ten plies, its reference line is the fifth-longest of the 19 French Defense codes.
| # | White | Black |
|---|---|---|
| 1 | e4 | e6 |
| 2 | d4 | d5 |
| 3 | Nd2 | c5 |
| 4 | exd5 | exd5 |
| 5 | Ngf3 | Nc6 |
Moves only C09 plays
Same as C08 up to 4...exd5, then:
- 5.Ngf3 The knight leaves g1 for f3, opening a line for the rook on h1, guarding the pawn on d4.
- 5...Nc6 The knight leaves b8 for c6, opening a line for the rook on a8.
Lines filed under C09
Both share their first ten plies, the whole reference line.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| French Defense: Tarrasch Variation, Open System, Main Line | (the shared start itself) | 10 | |
| French Defense: Tarrasch Variation, Open System, Main Line | 6.Bb5 Bd6 7.dxc5 Bxc5 8.O-O Ne7 9.c3 | 17 | White castled |
French Defense: Tarrasch Variation, Open System, Main Line
- 6.Bb5 The bishop leaves f1 for b5, opening a line for the rook on h1, attacking the knight on c6, pinning the knight on c6 to its king.
- 6...Bd6 The bishop leaves f8 for d6.
- 7.dxc5 The d-pawn takes the pawn on c5, covering b6 and d6, attacking the bishop on d6.
- 7...Bxc5 The bishop on d6 takes the pawn on c5, opening a line for the queen on d8.
- 8.O-O White castles kingside, opening a line for the queen on d1, guarding the pawn on g2.
The road to C09
- 1.e4 … 3.Nd2five earlier stops: B00, C00, C03
- 3...c5C07 Open System
- 4...exd5C08 Open System
- 5...Nc6C09
The position after 5...Nc6
White has brought out the knight on d2 and knight on f3; Black the knight on c6. White could capture with dxc5. The e-file is fully open.
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| B32 | Sicilian Defense: Open | six squares: b1, d2, e4, d5, d7, e7 |
| C04 | French Defense: Tarrasch Variation, Guimard Defense, Main Line | six squares: e4, c5, e6, f6, c7, g8 |
| C07 | French Defense: Tarrasch Variation, Open System | six squares: g1, f3, e4, c6, e6, b8 |
| D33 | Tarrasch Defense: Rubinstein System | six squares: c2, d2, e2, g2, c3, g3 |
| B30 | Sicilian Defense: Old Sicilian | seven squares: b1, d2, d4, e4, d5, d7, e7 |
| C03 | French Defense: Tarrasch Variation | eight squares: g1, f3, e4, c5, c6, e6, c7, b8 |
| D02 | Queen’s Pawn Game: Zukertort Variation | eight squares: b1, d2, e2, c5, c6, c7, e7, b8 |