big picture vs brainchild

big picture

noun
  • Used other than figuratively or idiomatically: see big, picture. 

  • The totality of a situation. 

brainchild

noun
  • A creation, original idea, or innovation, usually used to indicate the originators 

verb
  • To think up; to come up with. 

How often have the words big picture and brainchild occurred in a corpus of books? (source: Google Ngram Viewer )