Basketball on Shabbos

Answer

Assuming there is a kosher eruv, it isn’t technically forbidden, however, it isn’t in the spirit of shabbos to play ball. Rav Moshe Feinstein approved of the eruv in Kew Gardens Hills, NY, but instructed his talmid, Rav Peretz Steinberg, to go around the neighborhood on Shabbos and tell the people not to play ball. Therefore, you shouldn’t play ball on Shabbos.

Rabbi Meir Goldberg