Rat Defense: Harmonist
1. e4 d6 2. f4
The Rat Defense: Harmonist is a chess opening classified as ECO B00, reached after 1. e4 d6 2. f4. It is a line of the Rat Defense. Black is to move. 1 named line continues from this position.
In 12.6 million rated Lichess games (blitz and slower), this position was reached 13,059 times by this move order. White won 50%, 4% were drawn and Black won 46%. The most popular continuation is 2… Nf6 (46% of games).
Engine evaluation: +0.07 (Stockfish, depth 50; best line 2… Nf6 3. Nc3 c5 4. Nf3 Nc6 5. Bb5)
- ECO
- B00
- Moves
- 3 plies
- FEN
rnbqkbnr/ppp1pppp/3p4/8/4PP2/8/PPPP2PP/RNBQKBNR b KQkq - 0 2- PGN
1. e4 d6 2. f4
Analyse with Stockfish · Board image (SVG) · Open on Lichess
Results by rating
| Average rating | Games | White / draw / Black |
|---|---|---|
| 0-1499 | 2,997 | |
| 1500-1999 | 8,699 | |
| 2000+ | 1,363 | |
| All | 13,059 |
Most played moves
| Move | Games | White / draw / Black |
|---|---|---|
| 2… Nf6 | 5,947 (46%) | |
| 2… g6 | 1,671 (13%) | |
| 2… e5 | 1,456 (11%) | |
| 2… c6 | 900 (7%) | |
| 2… e6 | 819 (6%) | |
| 2… Nd7 | 681 (5%) | |
| 2… Nc6 | 469 (4%) | |
| 2… c5 | 414 (3%) |
Master games
603 over-the-board games are classified under this line (White 46%, draw 15%, Black 39%). The strongest:
- GM Ian Nepomniachtchi (2755) – GM Richard Rapport (2715) 1-0 · 10th Gashimov Mem Rapid · 2024-09-27
- GM Magnus Carlsen (2840) – GM Stamatis Kourkoulos-Arditis (2582) 1-0 · Titled Tue 3rd Feb 2026 · 2026-02-03
- GM Ian Nepomniachtchi (2755) – GM Onischuk, V. (2609) 1/2-1/2 · Titled Tue 29th Oct Late · 2024-10-29
- GM Anish Giri (2780) – GM Jose Fernando Cuenca Jimenez (2524) 1-0 · MrDodgy Invitational 2 · 2021-05-12
- GM Dmitry Andreikin (2710) – GM Luca Jr Moroni (2563) 1-0 · Titled Tue 17th Mar 2026 · 2026-03-17
Search all games of the Rat Defense: Harmonist and its sub-variations
Highest-rated Lichess games
- Lifvix01 (2809) – turututv (2589) 1-0 · 2026-09-07 · 180 + 0s
- tapkus (2651) – IM Masis68_am (2534) 0-1 · 2026-09-06 · 180 + 2s
- DoubleHelix2 (2625) – Shahin_Za_Shiraz (2529) 0-1 · 2026-09-07 · 180 + 2s
Comes from
Pirc Defense (1. e4 d6) 1. e4 d6
Continuations
- Rat Defense: Fuller Gambit B00 · 1. e4 d6 2. f4 d5 3. exd5 Nf6
More Rat Defense lines (all)
- Rat Defense: English Rat A41
- Rat Defense: English Rat, Lisbon Gambit A41
- Rat Defense: English Rat, Pounds Gambit A41
- Rat Defense: Balogh Defense A82
- Rat Defense: Antal Defense B00
- Rat Defense: Petruccioli Attack B00
- Rat Defense: Spike Attack B00
- Rat Defense: Accelerated Gurgenidze B06
- Rat Defense: Small Center Defense C00
Opening names and moves from the Lichess openings dataset; statistics from the Lichess open database, 2026-09 (CC0), sample of 12.6 million games, bots excluded; evaluations from Lichess cloud analysis (all CC0). Master games from The Week in Chess #920–#1664 by Mark Crowther, used with permission.