A doubleheader is a sporting event in which TWO games are played back-to-back. The crossword solutions for this term are OPENER (6 letters), SPLIT (5 letters), NIGHTCAP (8 letters), TWO (3 letters), and GAMES (5 letters). The OPENER refers to the first game of the doubleheader, the SPLIT is the break between the TWO games, the NIGHTCAP is the second game, TWO is the number of games played, and GAMES is the plural form of game.