有下的同好一起反应吧!!!!
规则写的清清楚楚的
A Regulation Game
(a) A regulation game consists of nine innings, unless extended because of a
tie score, or shortened:
(1) because the home team needs none of its half of the ninth inning or only a
fraction of it; or
(2) because the umpire calls the game.
EXCEPTION 1:
National association leagues may adopt a rule providing that one or both games
of a double-header shall be seven innings in length. In such games, any of
these Rules applying to the ninth inning shall apply to the seventh inning.
规则写的很明白，可以采用一场或是两场都只打七局，比赛中规则同一般９局长度的比赛
OFFICIAL AUSTRALIAN BASEBALL RULES 　即可搜寻到