Complex sentence: The 2006 World Thoroughbred Racehorse Rankings is an assessment of racehorses which raced in 2006 issued by the International Federation of Horseracing Authorities in January 2007.
Split into simpler sentences: The 2006 World Thoroughbred Racehorse Rankings is the 2006 edition of the World Thoroughbred Racehorse Rankings. It is an assessment of racehorses which was issued by the International Federation of Horseracing Authorities (IFHA) in January 2007.