Complex sentence: American Pharoah, ridden by jockey Victor Espinoza, was leaning back in the starting gate when it opened and was a touch late at the start, but he soon pulled out to an early lead, which he maintained for a gate-to-wire win.
Split into simpler sentences: American Pharoah, ridden by jockey Victor Espinoza, was leaning back in the starting gate when it opened and was a touch late at the start. But he soon pulled out to an early lead, which he maintained for a gate-to-wire win.