ECO E23
3 named openings and variations are classified as E23. ECO (Encyclopaedia of Chess Openings) codes group openings from A00 to E99 by their opening moves.
- Nimzo-Indian Defense: Spielmann Variation, Carlsbad VariationE231. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6 6. Nf3 Ne4 7. Bd2 Nxd2
- Nimzo-Indian Defense: Spielmann Variation, Romanovsky GambitE231. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6
- Nimzo-Indian Defense: Spielmann Variation, Stahlberg VariationE231. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6 6. Nf3 Ne4 7. Bd2 Nxc5