lay open vs tip one's hand

lay open

verb
  • To expose or reveal (something). 

  • To publish a patent for initial public review, prior to the formal application for registration. 

  • To open (something) through cutting or scissoring. 

tip one's hand

verb
  • To inadvertently reveal any secret, particularly a secret that puts one at an advantage or disadvantage. 

  • In card playing, to accidentally reveal one's cards or hand. 

How often have the words lay open and tip one's hand occurred in a corpus of books? (source: Google Ngram Viewer )