Some leagues within college baseball employ a mercy rule. This means if a team is up by 10 runs after seven innings (or six-and-a-half if the home team is ahead), the game can be called. In a seven-inning game, the rule is employed after the fifth inning. This rule is not used in NCAA tournament games. Some conferences choose to institute the mercy rule after seven innings on Sundays or in the final game of a conference series. This allows the visiting team to get an early start on traveling.
In professional baseball, the designated hitter (DH) is used in all games played in American League ballparks. The NCAA uses a DH; however, in college baseball a player may serve as both the pitcher and the DH (i.e., the pitcher bats). Furthermore, if that player is replaced as either pitcher or DH, he could remain in the game in his other role.
NCAA baseball games can be shortened to seven innings if two games are being played in one day. This can be in the case of a scheduled double-header, or if a make-up game is bring played on the same day as a regularly scheduled game. A seven-inning game may be played on the final day of a series conference. Tournament games are also nine innings. (The NCAA has encouraged schools and conferences to play as many full nine-inning games as possible throughout the season.)
Aggressive Base Running
In the NCAA, if a base runner collides "maliciously" with a defender who is trying to tag or force him out, the runner may be ejected at the umpire's discretion. Also, an "automatic double play" may be called if a sliding base runner tries to take out a defender who is attempting to complete a double play. In Major League Baseball, there is more discretion given for hard-nosed baseball in which a runner tries to break up a double play.