cinch vs walk in the park

cinch

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. 

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. 

walk in the park

noun
  • Something easy or pleasant. 

  • Used other than figuratively or idiomatically: A recreational walk in a park. 

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