C42

Petrov's Defense: Cozio Attack

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Statistics from Lichess

948,382 games: White 46.3% / Draw 7.8% / Black 45.8%

The moves played next. Pick one to see it on the board.
Next move	Games	White / Draw / BlackW / D / B
	920,747921K
	15,43415K
	5,1645,164
	2,3752,375
	2,0002,000
	681681
	643643
	541541

Rated Lichess games between players rated 1600 to 2500, from the Lichess opening explorer, updated Oct 31, 2026

Engine evaluation

+0.06 The position is about equal

Best play: 5... Qe7 6. d3 Nf6 7. Nc3 Nc6 8. Bg5 Qxe2+ 9. Bxe2 Be7 10. Nb5

Stockfish 19, depth 30, after the line's last move. Scores are in pawns, from White's side.

By rating

Rating changes little here: White scores 55% under 1400, 53% at 2200 and up and 51% in master games (wins plus half the draws).

Players	Games	White / Draw / BlackW / D / B
Under 1400	661K
1400–1799	1.1M
1800–2199	410K
2200 and up	38K
Masters, over the board	1,835

Master games

Rated blitz, rapid and classical Lichess games by rating band, and over-the-board games of players rated 2200+ from the Lichess masters database, updated Sep 27, 2026

Overview

Petrov's Defense: Cozio Attack (ECO C42, Open Games) is a variation of Petrov's Defense, reached after 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Qe2 (5 moves).

In 948,382 rated Lichess games between players rated 1600 to 2500, White won 46.3%, Black 45.8% and 7.8% were drawn. Black's most played move here is 5…Qe7, in 97% of those games.

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Description

Popularity by year

Petrov's Defense: Cozio Attack has lost ground since 2016: 0.028% of Lichess games in 2025, down from 0.041%.

0.041%0.028%0.045%

Numbers by year

Year	Share of games	Games
2016	0.041%	14,793
2017	0.038%	20,989
2018	0.045%	35,410
2019	0.044%	54,764
2020	0.044%	128,177
2021	0.041%	162,195
2022	0.039%	145,590
2023	0.035%	132,887
2024	0.031%	112,315
2025	0.028%	97,585
2026 (Jan–Apr)	0.027%	30,108

Share of rated Lichess games between players rated 1600 to 2500 (blitz, rapid and classical) that reach this position, by year; 2026: January to April. Which openings are rising and falling

Cite this page

Caissa Codex. “Petrov's Defense: Cozio Attack (C42)”. Lichess data as of 31 Oct 2026. https://chesscodex.org/openings/petrovs-defense-cozio-attack