In the dynamic arena of sports technology and engineering, engineers pay special attention to the energy stored and lost in equipment. Inflatable (and solid) balls are often governed by a coefficient of restitution that describes the interaction between the ball and a rigid plate. Proper dynamic characteristics are achieved by careful selection of materials, construction, and inflation pressure. After the ball leaves the factory, materials and construction remain relatively consistent, but the internal pressure is left up to the discretion of the athlete, who receives only a recommendation. A study was conducted to observe the relationship between over- and under-pressurization and energy loss at various levels of deformation.