bad boy vs tough case

bad boy

noun
  • An undesirable or difficult task. 

  • A male criminal. 

  • A powerful or impressive product or item. 

  • Used other than figuratively or idiomatically: see bad, boy. 

  • A man whose rebellious nature makes him dangerous and/or attractive. 

tough case

noun
  • A person who is difficult to work with. 

How often have the words bad boy and tough case occurred in a corpus of books? (source: Google Ngram Viewer )