closer vs relief pitcher

closer

noun
  • A relief pitcher who specializes in getting the last three outs of the game. See Wikipedia:closer (baseball) 

  • Someone or something that closes. 

  • Someone or something that concludes. 

  • Synonym of close (“the point at the end of a sales pitch when the consumer is asked to buy”) 

  • The last stone in a horizontal course, if smaller than the others; a piece of brick finishing a course. 

relief pitcher

noun
  • A pitcher who enters the game after the starting pitcher or another relief pitcher is removed due to injury, ineffectiveness, ejection from the game or fatigue. 

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