Complex sentence: In 1983, Auerbach named former Celtics player K.C. Jones coach of the Celtics who, starting in 1984, coached the Celtics to four straight appearances in the NBA Finals, winning championships in 1984 and 1986.
Split into simpler sentences: In 1983, Auerbach named former Celtics player K.C. Jones coach of the Celtics. Starting in 1984, Jones coached the Celtics to four straight appearances in the NBA Finals, winning championships in 1984 and 1986.