Complex sentence: His outstanding record and ease in winning made him the U.S. Outstanding Sprint Horse for 1990 and again in 1991, the first horse to do that since Great Above's dam, Ta Wee, in 1969-70.
Split into simpler sentences: His outstanding record and ease in winning made him the U.S. Outstanding Sprint Horse for 1990 and again in 1991. He became the first horse to do that since Great Above's dam, Ta Wee, in 1969-70.