Complex sentence: The 2005 World Thoroughbred Racehorse Rankings is an assessment of racehorses which raced in 2005 issued by the International Federation of Horseracing Authorities in January 2006.
Split into simpler sentences: The 2005 World Thoroughbred Racehorse Rankings is the 2005 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 2006.