Complex sentence: French champion jockey, Christophe Soumillon, has been booked to ride Overdose in all of his races in 2009 taking over the job from Andreas Suborics who had won on the sprinter 10 times.
Split into simpler sentences: French champion jockey, Christophe Soumillon, has been booked to ride Overdose in all of his races in 2009. Taking over the job from Andreas Suborics who has won on the sprinter 10 times.