Complex sentence: The game may still declared as a tie after 15 innings (18 innings before 2001), but if such a game occurred, a rematch will be arranged in the following day if possible, which usually scheduled the first game of the following day.
Split into simpler sentences: The game may still declared as a tie after 15 innings (18 innings before 2001). But if such a game occurred, a rematch will be arranged in the following day if possible, which usually scheduled the first game of the following day.