Complex sentence: At the time, the top four teams in each division made the playoffs, with the regular-season division winner playing against the fourth-place team and the regular-season runner-up playing the third-place team in the division semifinals.
Split into simpler sentences: At the time, the top four teams in each division made the playoffs. The regular-season division winner playing against the fourth-place team and the regular-season runner-up playing the third-place team in the division semifinals.