Indian Defense: Gibbins-Weidenhagen Gambit, Stummer Gambit
ECO A45
Move order
1. d4 Nf6 2. g4 Nxg4 3. e4 d6 4. Be2 Nf6 5. Nc3
Ideas
ECO A covers irregular and flank openings—systems that skip the main e4/d4 fight early. White builds a pawn center and keeps the position more closed than after 1. e4. 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.