A cikin wasannin da yawa, sandunan ƙwallon ƙafa suna a kowane ƙarshen filin wasa, akwai ginshiƙai guda biyu (ko tsaye) waɗanda ke tallafawa sandar kwance. A wasu wasannin, kamar ƙwallon ƙafa ko hockey, makasudin shine a wuce ƙwallon ko puck tsakanin ginshiƙan da ke ƙasa da sandar ƙetare, yayin da a wasu, kamar waɗanda suka dogara da rugby, dole ne ƙwallon ya wuce kan sandar ƙetare maimakon. Tambaya: Yaya aka tsara sandunan ƙwallon ƙafa a cikin wasanni da yawa?
biyu tsaye posts (ko uprights) goyon bayan a kwance crossbar