explain vs rope in

explain

verb
  • To make plain, manifest, or intelligible; to clear of obscurity; to illustrate the meaning of. 

  • To give a valid excuse for past behavior. 

  • To make something plain or intelligible. 

rope in

verb
  • To cause (someone) to become involved in something they are reluctant to do; to draw into something. 

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