prizefight vs semifinal

prizefight

noun
  • A professional boxing match, in which two boxers compete for a prize (usually money). 

semifinal

noun
  • A competition that narrows a field of contestants (semifinalists) to a set of finalists, for a subsequent final. 

  • A playoff in the round with only four players or teams left, the stage before the final. 

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