gridiron vs international rules football

gridiron

noun
  • American and Canadian football, particularly when used to distinguish from other codes of football. 

  • An openwork frame on which vessels are placed for examination, cleaning, and repairs. 

  • A raised framework from which lighting is suspended. 

  • The field on which American football is played. 

  • An iron rack or grate used for broiling meat and fish over coals. 

  • An instrument of torture on which people were secured before being burned by fire. 

  • Any object resembling the rack or grate. 

verb
  • To mark or cover with lines; to crisscross. 

  • To purchase land so that the remaining adjacent sections are smaller than the minimum area purchasable as freehold, thus excluding potential freeholders. 

international rules football

noun
  • A sport created as a mixture of Australian rules football and Gaelic football, to allow international matches between Australia and Ireland. 

How often have the words gridiron and international rules football occurred in a corpus of books? (source: Google Ngram Viewer )