Rat Defense: Complete Guide

A universal Black setup — d6 first, then wait and see what White commits to before choosing a plan. Drill every main line against an adaptive engine, backed by real Lichess win rates and Stockfish evaluations.

28 variations 15,307,074 total games Avg Stockfish +0.51

Play the main line: Rat Defense: Small Center Defense

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All 28 variations of the Rat Defense

Openings & Plans Rat Defense: Small Center Defense ECO C00 6M games Openings & Plans Rat Defense: Harmonist ECO B00 2M games Openings & Plans Rat Defense: Antal Defense ECO B00 1M games Openings & Plans Rat Defense: Antal Defense: Nf3 ECO B00 1M games Openings & Plans Rat Defense: English Rat ECO A41 769K games Openings & Plans Rat Defense: Harmonist: Nf6 ECO B00 616K games Openings & Plans Rat Defense: Small Center Defense: Nf3 ECO C00 530K games Openings & Plans Rat Defense: Harmonist: g6 ECO B00 432K games Openings & Plans Rat Defense: Balogh Defense ECO A82 343K games Openings & Plans Rat Defense: Harmonist: c6 ECO B00 226K games Openings & Plans Rat Defense: Small Center Defense: Nc3 ECO C00 204K games Openings & Plans Rat Defense: Antal Defense: Nc3 ECO B00 150K games Openings & Plans Rat Defense: Harmonist: e5 ECO B00 122K games Openings & Plans Rat Defense: Accelerated Gurgenidze ECO B06 116K games Gambits Rat Defense: English Rat, Lisbon Gambit ECO A41 86K games Openings & Plans Rat Defense: Small Center Defense: d5 ECO C00 70K games Openings & Plans Rat Defense: Antal Defense: c4 ECO B00 63K games Openings & Plans Rat Defense: Harmonist: e6 ECO B00 54K games Openings & Plans Rat Defense: Antal Defense: f4 ECO B00 31K games Openings & Plans Rat Defense: Small Center Defense: c4 ECO C00 26K games Openings & Plans Rat Defense: Petruccioli Attack ECO B00 21K games Openings & Plans Rat Defense: Small Center Defense: Bd3 ECO C00 17K games Openings & Plans Rat Defense: Spike Attack ECO B00 16K games Openings & Plans Rat Defense: Antal Defense: Bd3 ECO B00 14K games Openings & Plans Rat Defense: Small Center Defense: f4 ECO C00 10K games Openings & Plans Rat Defense: Harmonist: Nd7 ECO B00 10K games Gambits Rat Defense: English Rat, Pounds Gambit ECO A41 6K games Gambits Rat Defense: Fuller Gambit ECO B00 796 games

Frequently asked questions about the Rat Defense

What is the rat in chess?

The Rat is a chess opening family with 28 variations covered on Chessy. Over 15 million Lichess games have reached these positions across all rating levels.