Complex sentence: He guided with difficulty the Timberwolves to their first-ever playoff berth in the 1996--97 season, his first full season as an NBA head coach, and to a franchise-record 50 victories in 1999--2000 which was duplicated in 2001--2002.
Split into simpler sentences: He guided with difficulty the Timberwolves to their first-ever playoff berth in the 1996--97 season, his first full season as an NBA head coach. They went on to a franchise-record 50 victories in 1999--2000 which was duplicated in 2001--2002.