draft horse vs horse racing

draft horse

noun
  • A horse of a race specifically bred for such work, heavier and stronger than a mount. 

  • A horse used for muscular work, other than carrying a rider and/or load, such as pulling a cart, plow or log. 

horse racing

noun
  • A sport where horses and their jockeys compete to race around a track the fastest. 

How often have the words draft horse and horse racing occurred in a corpus of books? (source: Google Ngram Viewer )