head case vs screwball

head case

noun
  • Used other than figuratively or idiomatically: see head, case. 

screwball

noun
  • One who behaves in a crazy manner. 

  • A pitch thrown with added pressure by the index finger and a twisting wrist motion resulting in a motion to the right when thrown by a right-handed pitcher. 

adj
  • Crazy, offbeat, bizarre, zany, or weird. 

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