College baseball pitcher Andrew Sanchez (plaintiff) was struck in the head and injured by a line drive baseball hit using an aluminum bat manufactured by Hillerich & Bradsby Company (H&B) (defendant). Prior to the start of the 1999 baseball season, Sanchez signed a disclaimer form acknowledging that playing carried a risk of injury. Sanchez filed suit against H&B, and others, alleging that the design and use of the aluminum bat significantly increased the inherent risk in the sport that a pitcher would be hit by a line drive. The trial court granted H&B’s motion for summary judgment on the ground that Sanchez would not be able to prove that his injuries resulted from the alleged increased risk the particular bat posed to pitchers. Sanchez appealed.