Spencer quits Ballydoyle Irish champion jockey Jamie Spencer has resigned as stable jockey at Ballydoyle.A brief statement issued by his former employers stated, ´Jamie Spencer has informed Ballydoyle Racing Stables of his decision to resign his position as the yard´s retained jockey.´´Jamie is a young jockey with alot of talent, and has a long career ahead of him. All the team at Ballydoyle wish him the very best,´ said spokesperson Richard Henry.John Murtagh is 4/5 favourite with Cashmans to replace Spencer as Aidan O´Brien´s number one jockey for 2005.