Rat Defense: Harmonist
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Statistics from Lichess
3,352,096 games: White 50.1% / Draw 3.8% / Black 46.1%
| Next move | Games | White / Draw / BlackW / D / B |
|---|---|---|
| 1,354,5191.4M | ||
| 482,726483K | ||
| 399,628400K | ||
| 252,129252K | ||
| 233,425233K | ||
| 193,592194K | ||
| 139,758140K | ||
| 113,573114K |
Rated Lichess games between players rated 1600 to 2500, from the Lichess opening explorer, updated Nov 5, 2026
Engine evaluation
+0.05 The position is about equal
Best play: 2... c5 3. Nf3 g6 4. d4 cxd4 5. Qxd4 Nf6 6. Nc3 Bg7 7. Be3
Stockfish 19, depth 30, after the line's last move. Scores are in pawns, from White's side.
By rating
The stronger the players, the worse this line does for White: White scores 53% under 1400, 50% at 2200 and up and 55% in master games (wins plus half the draws).
| Players | Games | White / Draw / BlackW / D / B |
|---|---|---|
| Under 1400 | 602K | |
| 1400–1799 | 2M | |
| 1800–2199 | 2M | |
| 2200 and up | 93K | |
| Masters, over the board | 371 |
Master games
- Nepomniachtchi, I. – Rapport, R.
- Gashimov, V. – Bologan, V.
- Ivanchuk, V. – Can, E.
- Short, N. D. – Timman, J. H.
- Bartel, M. – Krasenkow, M.
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 26, 2026
Overview
Rat Defense: Harmonist (ECO B00, Semi-Open Games) is a variation of the Pirc Defense, reached after 1. e4 d6 2. f4 (2 moves).
In 3,352,096 rated Lichess games between players rated 1600 to 2500, White won 50.1%, Black 46.1% and 3.8% were drawn. Black's most played move here is 2…Nf6, in 40% of those games.
It continues into one named variation, Rat Defense: Fuller Gambit.
Written from the Lichess opening list and explorer. Know this line well? Write about it.
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How to play against the Rat Defense: Harmonist
2…e5 scores best for Black: 49.4%, with Black winning 47.6% and White 48.8% of 400K games. The most played, 2…Nf6, scores 48.5% in 1.4M games, and 2…e6 scores lowest: 44.6%. Stockfish's first choice is 2…c5.
Main answers: those played in at least 5% of these games. Score: Black's wins plus half the draws, in rated Lichess games between players rated 1600 to 2500. How to play against other popular openings
Popularity by year
The Rat Defense: Harmonist dipped to 0.11% of Lichess games in 2020 and has recovered since: 0.14% in 2025.
Numbers by year
| Year | Share of games | Games |
|---|---|---|
| 2016 | 0.13% | 46,220 |
| 2017 | 0.13% | 73,394 |
| 2018 | 0.13% | 100,482 |
| 2019 | 0.13% | 159,532 |
| 2020 | 0.11% | 332,417 |
| 2021 | 0.12% | 454,765 |
| 2022 | 0.13% | 491,393 |
| 2023 | 0.13% | 496,700 |
| 2024 | 0.14% | 491,983 |
| 2025 | 0.14% | 483,935 |
| 2026 (Jan–Apr) | 0.14% | 157,972 |
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
Variations (1)
Cite this page
Caissa Codex. “Rat Defense: Harmonist (B00)”. Lichess data as of 5 Nov 2026. https://chesscodex.org/openings/rat-defense-harmonist