WAG vs wild card

WAG

noun
  • A wife or girlfriend of a sports star or other celebrity, originally and especially of an association football player. 

  • A wild-assed guess; a rough estimate. 

wild card

noun
  • A competitor or team that is allowed to compete in a tournament despite not reaching the normal standards to qualify for inclusion. 

  • A card that can be assigned any value or used to substitute for any needed card. 

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