Polish Opening: Dutch Defense
ECO A00
Move order
1. b4 f5
Ideas
ECO A covers irregular and flank openings—systems that skip the main e4/d4 fight early. White gains queenside space immediately—the Sokolsky / Polish family. This entry names the opening after the first moves. Use the diagram and SAN list to recognize the tabiya, then try the line against Maia to explore typical plans in practice.