EntityQ1919685· pop 17· linked from 605 articleschess theorySign in to saveConnectionsSoviet UnionConceptWilhelm SteinitzEntitySicilian DefenceEntityElo rating systemEntityPetrov's DefenceEntityalgebraic notationEntityGrünfeld DefenceEntityPhilidor DefenceEntitychess tacticEntityList of ECO codesEntitychess titleEntitypassed pawnEntitychess engineEntitychess annotation symbolEntityonline chessEntitySpainCountryPortugalCountryGermanEntityEnglandEntitychessEntityCategoriesChess terminologyChess theory