Complex sentence: With Pollard's chest crushed by the weight of the fallen horse, and his ribs and arm broken, Howard tried three jockeys before settling on George Woolf, an already successful rider and old friend of Pollard, to ride Seabiscuit.
Split into simpler sentences: With Pollard's chest crushed by the weight of the fallen horse, and his ribs and arm broken, Howard had to find a new jockey. After trying three, he settled on George Woolf, an already successful rider and old friend of Pollard, to ride Seabiscuit.