cinch vs soft option

cinch

verb
  • To tighten down. 

  • To bring to certain conclusion. 

  • In the game of cinch, to protect (a trick) by playing a higher trump than the five. 

noun
  • Something that is very easy to do. 

  • A firm hold. 

  • A variety of auction pitch in which a draw to improve the hand is added, and the five of trumps (called "right Pedro") and the five of the same colour (called "left Pedro", and ranking between the five and the four of trumps) are each worth five. Fifty-one points make a game. 

  • A simple saddle girth used in Mexico. 

  • Something that is obvious or certain to occur; a sure thing. 

soft option

How often have the words cinch and soft option occurred in a corpus of books? (source: Google Ngram Viewer )