king of the castle vs top gun

king of the castle

noun
  • An individual who assumes a position of greater importance, authority, or prominence than others. 

  • A children's game in which one player is located on something elevated and other players attempt to take his or her place. 

top gun

noun
  • An expert gunner or gunman. 

  • Someone most highly rated. 

How often have the words king of the castle and top gun occurred in a corpus of books? (source: Google Ngram Viewer )