exacta vs side bet

exacta

noun
  • A bet in which the bettor must correctly pick the two runners who finish first and second, in the correct order. 

side bet

noun
  • A bet on some aspect of a game or competition that is not the main bet of the game or the prize of the competition; proposition bet. 

  • An investment of time, money, or resources that reinforces one's commitment to a course of action. 

  • An investment or risk undertaken by a company that is not part of its core business. 

How often have the words exacta and side bet occurred in a corpus of books? (source: Google Ngram Viewer )