long shot vs odds on

long shot

noun
  • A master shot, the primary wide shot of a scene into which the closeups will be edited later. 

  • A shot fired at a distant target. 

  • Something unlikely; something that has little chance of happening or working. 

odds on

adj
  • Likely: alternative spelling of odds-on 

How often have the words long shot and odds on occurred in a corpus of books? (source: Google Ngram Viewer )