Complex sentence: It was Decathlon's only loss of the year, as he went 8 for 9, and he was named American Champion Sprint Horse for 1957, after having also won the award in 1956.
Split into simpler sentences: It was Decathlon's only loss of the year, as he went 8 for 9. He was named American Champion Sprint Horse for 1957, after having also won the award in 1956.