Abstract: A ball having an outer chamber and a first center of volume contains an inner chamber which is substantially smaller than the outer chamber. The inner chamber has a body portion and a neck portion, the neck portion extending between the body portion and the outer skin of the outer chamber. The neck portion is the only connection between the inner and outer chambers and comprises a flexible tube for permitting the inner chamber to swing back and forth within the outer chamber about the connection. The inner chamber contains a selected amount of a medium much denser than air and when the ball is in use the ball has eccentric and unpredictable flight characteristics.

Abstract: An inflatable ball is disclosed capable of having eccentric flight and bounce characteristics. The inflatable ball has an outer inflatable chamber having a first sealable orifice and an outer skin. An inner fillable chamber having a second sealable orifice and an integral inner skin is also provided. The second sealable orifice is in the outer skin of the outer inflatable chamber. The inner fillable chamber is substantially smaller than the outer inflatable chamber and is located within the outer inflatable chamber generally adjacent the outer skin thereof. The inner fillable chamber is attached to the outer skin at the second sealable orifice. In the preferred embodiment the ball is spherical and the first sealable orifice is diametrically opposed to the second sealable orifice. The second sealable orifice may be provided with locking ridges to secure a plug therein.