panic button vs sweet spot

panic button

noun
  • An emergency button which, when pressed, alerts authorities of danger or triggers an alarm system. 

sweet spot

noun
  • Any place that is optimal for obtaining a certain desirable effect or result. 

  • Any of several places on a bat, racquet, etc., with which to hit a ball, resulting in the latter rebounding with some optimal desirable effect, such as minimum vibration or maximum velocity. 

  • The clitoris, prostate gland, or other center of sexual pleasure. 

  • Any set of conditions that is optimal for obtaining a certain desirable effect or result. 

How often have the words panic button and sweet spot occurred in a corpus of books? (source: Google Ngram Viewer )