Complex sentence: Prove It had a highly successful racing career that included wins in the prestigious Santa Anita Handicap (1961) and Hollywood Gold Cup (1962), plus he set an Arlington Park track record in the 1962 Benjamin F. Lindheimer Handicap.
Split into simpler sentences: Prove It had a highly successful racing career that included wins in the prestigious Santa Anita Handicap (1961) and Hollywood Gold Cup (1962). He also set an Arlington Park track record in the 1962 Benjamin F. Lindheimer Handicap.