Great Sports Illus. article on buildup to Patterson v Ingo I. https://www.si.com/vault/1959/06/22/607138/ingos-right-and-floyds-peekaboo-in-collision "Johansson adds his own extraordinary Swedish calisthenics and at least two rounds of punching on a strange contraption, a Swedish girls' slungboll, which is normally hurled in girlish imitation of the hammer throw. Suspended from a bang board by its 18-inch strap handle, it is much harder to hit consistently than the ordinary speed bag, which moves with a swift but definite rhythm. The slungboll moves with the approximate speed and unpredictability of an opponent's bobbing, weaving head. Johansson's reflexes are being trained, in other words, to catch Patterson's head going east with a Johansson punch going west"
