fill in vs pinch-hit

fill in

verb
  • To substitute for somebody or something. 

  • To complete a form or questionnaire with requested information. 

  • To beat up; to physically assault. 

  • To fill; to replace material that is absent or has been removed. 

  • To inform somebody, especially to supply someone missing or missed information. 

pinch-hit

verb
  • To do something in the place of another person who is not able to perform or is less skilled; to substitute or stand in for somebody. 

  • To bat in place of another player 

How often have the words fill in and pinch-hit occurred in a corpus of books? (source: Google Ngram Viewer )