Complex sentence: With 13 victories as a three-year-old Buckpasser became the first horse to earn more than $1 million dollars before the age of four and he was named the 1966 American Horse of the Year.
Split into simpler sentences: With 13 victories as a three-year-old, Buckpasser became the first horse to earn more than $1 million before the age of four. He was named the 1966 American Horse of the Year.