| Name | ECO | Main line length |
|---|
| Modern Defense | B06 | 2 plies |
| Modern Defense: Fianchetto Gambit | B06 | 4 plies |
| Modern Defense: Norwegian Defense | B06 | 4 plies |
| Modern Defense | B06 | 4 plies |
| Modern Defense: Lizard Defense, Pirc-Diemer Gambit | A40 | 5 plies |
| Modern Defense: Three Pawns Attack | B06 | 5 plies |
| Modern Defense: Standard Line | B06 | 5 plies |
| Modern Defense: Westermann Gambit | B06 | 5 plies |
| Modern Defense: Bishop Attack | B06 | 5 plies |
| Modern Defense: Wind Gambit | B06 | 5 plies |
| Modern Defense: Neo-Modern Defense | A41 | 6 plies |
| Modern Defense | A41 | 6 plies |
| Modern Defense: Standard Defense | B06 | 6 plies |
| Modern Defense: Lizard Defense, Mittenberger Gambit | B06 | 6 plies |
| Modern Defense: Mongredien Defense, with Nf3 | B06 | 6 plies |
| Modern Defense: Bishop Attack, Bücker Gambit | B06 | 6 plies |
| Modern Defense: Mongredien Defense, with Nc3 | B06 | 6 plies |
| Modern Defense: Modern Pterodactyl | B06 | 6 plies |
| Modern Defense: Averbakh System | A42 | 7 plies |
| Modern Defense: Pseudo-Austrian Attack | B06 | 7 plies |
| Modern Defense: Geller's System | B07 | 7 plies |
| Modern Defense: Two Knights Variation | B06 | 7 plies |
| Modern Defense: Randspringer Variation | A42 | 8 plies |
| Modern Defense: Semi-Averbakh Variation, Polish Variation | A04 | 8 plies |
| Modern Defense: Kotov Variation | A42 | 8 plies |
| Modern Defense: Norwegian Defense, Norwegian Gambit | B06 | 8 plies |
| Modern Defense: Two Knights Variation, Suttles Variation | B06 | 8 plies |
| Modern Defense: Semi-Averbakh Variation, Pterodactyl Variation | A04 | 8 plies |
| Modern Defense: Pterodactyl Variation | B27 | 8 plies |
| Modern Defense: Bishop Attack, Monkey's Bum | B06 | 8 plies |
| Modern Defense: Averbakh Variation, Pseudo-Sämisch | A42 | 9 plies |
| Modern Defense: Anti-Modern | B06 | 9 plies |
| Modern Defense: Gurgenidze Defense | B06 | 10 plies |
| Modern Defense: Semi-Averbakh Variation, Pterodactyl Variation Declined | B06 | 10 plies |
| Modern Defense: Semi-Averbakh Variation, Pterodactyl Variation Accepted | A04 | 10 plies |
| Modern Defense: Beefeater Variation | A40 | 10 plies |
| Modern Defense: Dunworthy Variation | B06 | 10 plies |
| Modern Defense: Masur Gambit | B06 | 10 plies |
| Modern Defense: Two Knights Variation, Suttles Variation, Tal Gambit | B06 | 12 plies |