Colle System — opening family
3 catalogued lines · ECO A04–A40
The shortest catalogued line of the family runs 1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 Qa5+ — the position below. The continuation chips count how many catalogued lines extend this head with each next move; explore the full tree below and play any branch against the engine.
Variations tree of the Colle System family
Click any move to jump to that position; switch branches at any point with the alternative moves. Test your knowledge plays the shown position against the engine.
Start
All 3 lines
| Name | ECO | Main line length |
|---|---|---|
| Colle System: Pterodactyl Variation | A40 | 8 plies |
| Colle System: Rhamphorhynchus Variation | A04 | 8 plies |
| Colle System: Siroccopteryx Variation | A40 | 10 plies |