Complex sentence: Drake improved upon their first winning season since the 1986-1987 season, making their first NCAA tournament appearance since their run to the Elite Eight in 1971 and their first postseason appearance since their National Invitational Tournament appearance in 1986.
Split into simpler sentences: Drake improved upon their first winning season since the 1986-1987 season. They will make their first NCAA tournament appearance since their run to the Elite Eight in 1971 and their first postseason appearance since their National Invitational Tournament appearance in 1986.