Complex sentence: When he was three-years-old Rock Sand won the 2,000 Guineas Stakes, Epsom Derby, St. Leger Stakes, St. James's Palace Stakes and was third in the Eclipse Stakes behind Ard Patrick and Sceptre.
Split into simpler sentences: When he was three years old, he won the 2,000 Guineas Stakes, Epsom Derby, St. Leger Stakes, and St. James's Palace Stakes. He also finished third in the Eclipse Stakes behind Ard Patrick and Sceptre.