Pirate vs Rover

Pirate

noun
  • someone connected with Bristol Rovers Football Club, as a fan, player, coach etc. 

  • someone connected with any of a number of sports teams known as the Pirates, as a fan, player, coach etc. 

Rover

noun
  • someone connected with Blackburn Rovers FC, as a fan, player, coach etc. 

  • A member of the senior section of the Boy Scout movement catering for men of age 18 upwards, now disbanded. 

  • someone connected with any number of teams called the Rovers, as a fan, player, coach etc. 

name
  • A former make of British motor car. 

  • A stereotypical name for a dog. 

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