- ECO code
- C42
- Moves
- 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Nc6
- Family
- Petrov's Defense
- To move
- White
- Master games
- 337
- Average game length
- 41 moves
- Years covered
- 1879–2026
Petrov's Defense: Classical Attack, Mason-Showalter Variation is the opening filed under ECO code C42, reached after 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Nc6. It belongs to the Petrov's Defense family and is known as the Classical Attack, Mason-Showalter Variation; in the resulting position it is White to move.
Katuranga's collection of 138,070 master games contains 337 games on this line — the 282nd most played opening in the collection. The oldest game on this line is from 1879 and the most recent from 2026. The busiest decade in this collection is the 2000s, with 173 games. An average game here lasts 41 moves.
White wins 28% of those games, 60% end in a draw, and Black wins 12%. Compared with the collection average (White 37%, draws 35%, Black 28%), Black scores worse here by 16 percentage points. Draws are more common here than usual, by 25 points.
From this position the most popular move is 7.O-O, played in 333 games, followed by 7.Qe2 (2) and 7.Nbd2 (1). After 7.O-O White scores 28% and Black 12%.
The name that appears most often on the White side of this line is Shirov,A (34 games); on the Black side, Kramnik,V (37).
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Results in master games
- White 28% (95)
- Draws 60% (201)
- Black 12% (41)
Most played continuations
| Move | Games | White / draws / Black | Leads into |
|---|---|---|---|
| 7.O-O | 333 | 28/60/12 | — |
| 7.Qe2 | 2 | 50/50/0 | — |
| 7.Nbd2 | 1 | 100/0/0 | — |
| 7.Nc3 | 1 | 100/0/0 | — |
How the position is reached
- King's Pawn Game · 1.e4 · 62,859 games
- King's Pawn Game · 1.e4 e5 · 24,632 games
- King's Knight Opening · 1.e4 e5 2.Nf3 · 21,895 games
- Petrov's Defense · 1.e4 e5 2.Nf3 Nf6 · 2,341 games
- Petrov's Defense · 1.e4 e5 2.Nf3 Nf6 3.Nxe5 · 1,694 games
- Petrov's Defense · 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 · 1,655 games
- Petrov's Defense · 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 · 1,578 games
- Petrov's Defense · 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 · 1,578 games
- Petrov's Defense: Classical Attack · 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 · 894 games
Played most often by
As White
- Shirov,A 34
- Anand,V 29
- Grischuk,A 19
As Black
- Kramnik,V 37
- Gelfand,B 20
- Anand,V 17
Games per decade
- 1870s 1
- 1890s 1
- 1910s 1
- 1980s 10
- 1990s 44
- 2000s 173
- 2010s 49
- 2020s 58
Master games on this line
| White | Black | Result | Year | Events |
|---|---|---|---|---|
| Niemann,Hans Moke | Abdusattorov,Nodirbek | 1/2-1/2 | 2026 | 88th Tata Steel Masters |
| Erigaisi,Arjun | Theodorou,Nikolas | 1-0 | 2026 | 3rd UzChess Cup Masters |
| Niemann,Hans Moke | Abdusattorov,Nodirbek | 1/2-1/2 | 2026 | Chess.com Open PlayIn1 |
| Van Foreest,Jorden | Abdusattorov,Nodirbek | 1/2-1/2 | 2026 | GCT Super Blitz Croatia |
| Aronian,L | Yu Yangyi | 1-0 | 2025 | Esports World Cup LC Lose |
| Erigaisi,Arjun | Nepomniachtchi,I | 1/2-1/2 | 2025 | Esports World Cup 2025 |
Frequently asked questions
What is the Petrov's Defense: Classical Attack, Mason-Showalter Variation?
It is the opening with ECO code C42, reached after 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Nc6. It belongs to the Petrov's Defense family.
Is the Petrov's Defense: Classical Attack, Mason-Showalter Variation good for White or for Black?
In 337 master games on this line White wins 28%, 60% are drawn and Black wins 12%. The collection average is White 37%, draws 35%, Black 28% — so this line is no worse than usual for White than the field as a whole.
What is the main continuation of the Petrov's Defense: Classical Attack, Mason-Showalter Variation?
7.O-O — played in 333 of the master games on this line.
Which grandmasters play the Petrov's Defense: Classical Attack, Mason-Showalter Variation?
On the White side Shirov,A (34), Anand,V (29), Grischuk,A (19); on the Black side Kramnik,V (37), Gelfand,B (20), Anand,V (17).
Every number on this page is computed from Katuranga's master game collection; names and ECO codes follow the lichess opening book (CC0).
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