Elliot Maddox (plaintiff), a New York Yankees baseball player, was injured during a game played at Shea Stadium which was owned by the City of New York (NYC) (defendant). After Maddox had chased and caught up with a ball in right centerfield, he prepared to throw the ball back into the infield when his right foot got stuck in a patch of mud or wet grass and his knee buckled, causing him injuries. Maddox and other players knew that portions of the field were “awfully wet” with “some mud,” yet did not request to sit the game out or send in a replacement player. Maddox brought suit against NYC for negligence. The trial court denied NYC’s motion for summary dismissal on the ground that a genuine issue remained whether NYC could assert the affirmative defense of assumption of risk. NYC appealed the decision.