Gordian knot vs grabber

Gordian knot

noun
  • The legendary knot tied to a pole near the temple of Zeus in Gordium. 

  • Any intricate and complex problem having a simple solution. 

grabber

noun
  • One who, or that which, grabs or seizes. 

  • A machine in an amusement arcade containing prizes which the player must attempt to pick up with a mechanical grabbing arm. 

  • A line of dialogue, etc. that captures the viewer's attention. 

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