Nimzo-Indian Defense: Three Knights Variation
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3
The Nimzo-Indian Defense: Three Knights Variation is a chess opening classified as ECO E21, reached after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3. It is a line of the Nimzo-Indian Defense. Black is to move. 5 named lines continue from this position.
In 12.6 million rated Lichess games (blitz and slower), this position was reached 4,052 times by this move order. White won 48%, 5% were drawn and Black won 47%. The most popular continuation is 4… O-O (26% of games).
Engine evaluation: +0.05 (Stockfish, depth 65; best line 4… O-O 5. Bd2 d5 6. e3 b6 7. cxd5)
- ECO
- E21
- Moves
- 7 plies
- FEN
rnbqk2r/pppp1ppp/4pn2/8/1bPP4/2N2N2/PP2PPPP/R1BQKB1R b KQkq - 3 4- PGN
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3
Analyse with Stockfish · Board image (SVG) · Open on Lichess
Results by rating
| Average rating | Games | White / draw / Black |
|---|---|---|
| 0-1499 | 441 | |
| 1500-1999 | 2,318 | |
| 2000+ | 1,293 | |
| All | 4,052 |
Most played moves
| Move | Games | White / draw / Black |
|---|---|---|
| 4… O-O | 1,065 (26%) | |
| 4… b6 | 724 (18%) | |
| 4… c5 | 715 (18%) | |
| 4… Bxc3+ | 507 (13%) | |
| 4… d5 | 482 (12%) | |
| 4… Ne4 | 395 (10%) | |
| 4… Nc6 | 42 (1%) | |
| 4… h6 | 41 (1%) |
Master games
5,300 over-the-board games are classified under this line (White 40%, draw 27%, Black 33%). The strongest:
- LCZero 0.31-dag-e429eeb-BT3-2790000 (3642) – Stockfish dev-20231010-00263636 (3673) 1/2-1/2 · TCEC 25 Superfinal 2023 · 2023-10-12
- Stockfish dev-20231010-00263636 (3673) – LCZero 0.31-dag-e429eeb-BT3-2790000 (3642) 1/2-1/2 · TCEC 25 Superfinal 2023 · 2023-10-12
- LCZero 0.30-dag-9a9c42d_784968 (3599) – Stockfish dev16_20221027 (3625) 1/2-1/2 · TCEC 23 Superfinal 2022 · 2022-10-31
- Stockfish dev16_20221027 (3625) – LCZero 0.30-dag-9a9c42d_784968 (3599) 1/2-1/2 · TCEC 23 Superfinal 2022 · 2022-10-31
- GM Magnus Carlsen (2882) – GM Liren Ding (2805) 1/2-1/2 · 7th Sinquefield Cup 2019 · 2019-08-25
Search all games of the Nimzo-Indian Defense: Three Knights Variation and its sub-variations
Highest-rated Lichess games
- GM cutemouse83 (2919) – GladiatorDefence (2800) 1/2-1/2 · 2026-09-04 · 180 + 0s
- NM Andrey11976 (2790) – Nana_jede_cevape (2893) 0-1 · 2026-09-05 · 180 + 0s
- ScareCCrow06PL (2832) – Chess1Love0 (2811) 1-0 · 2026-09-02 · 180 + 0s
Comes from
Nimzo-Indian Defense (3. Nc3 Bb4) 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4
Continuations
- Nimzo-Indian Defense: Three Knights Variation, Korchnoi Variation E21 · 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 c5 5. d5
- Nimzo-Indian Defense: Romanishin Variation (5… O-O 6. Bg2) E20 · 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 c5 5. g3 O-O 6. Bg2
- Nimzo-Indian Defense: St. Petersburg Variation (5… Ne4 6. Qc2) E43 · 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 b6 5. e3 Ne4 6. Qc2
- Nimzo-Indian Defense: St. Petersburg Variation (7… O-O 8. O-O) E43 · 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 Bxc3+ 5. bxc3 b6 6. e3 Bb7 7. Bd3 O-O 8. O-O
- Nimzo-Indian Defense: Romanishin Variation, English Hybrid E20 · 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 c5 5. g3 cxd4 6. Nxd4 O-O 7. Bg2 d5 8. cxd5 Nxd5
More Nimzo-Indian Defense lines (all)
- Nimzo-Indian Defense: Dilworth Gambit E20
- Nimzo-Indian Defense: Kmoch Variation E20
- Nimzo-Indian Defense: Mikenas Attack E20
- Nimzo-Indian Defense: Romanishin Variation (3… Bb4 4. g3) E20
- Nimzo-Indian Defense: Three Knights Variation, Euwe Variation E21
- Nimzo-Indian Defense: Three Knights Variation, Shocron Gambit E21
- Nimzo-Indian Defense: Spielmann Variation E22
- Nimzo-Indian Defense: Spielmann Variation, Carlsbad Variation E23
- Nimzo-Indian Defense: Spielmann Variation, Romanovsky Gambit E23
- Nimzo-Indian Defense: Spielmann Variation, Stahlberg Variation (7. Bd2 Nxc5) E23
- Nimzo-Indian Defense: Spielmann Variation, Stahlberg Variation (8… f5 9. g3) E23
- Nimzo-Indian Defense: Sämisch Variation (3… Bb4 4. a3) E24
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.