Réti Opening: Reversed Blumenfeld Gambit
ECO A09
Move order
1. Nf3 d5 2. c4 d4 3. e3 c5 4. b4
Ideas
ECO A covers irregular and flank openings—systems that skip the main e4/d4 fight early. White develops a knight and keeps flexible transpositions into d4 or c4 setups. This entry tracks a longer branch in the opening tree. Use the diagram and SAN list to recognize the tabiya, then try the line against Maia to explore typical plans in practice.