first base vs lead off

first base

noun
  • The base after home plate in a counter-clockwise path around a baseball infield. 

  • Completion of the first phase of an activity. 

  • Kissing, regarded as the first phase of a sexual relationship. 

  • The betting spot located immediately to the left of the dealer, which is first to receive cards and first to act. 

lead off

noun
  • The short distance that a player stands away from their current base. 

  • The first batter in the batting order. 

  • The first batter of an inning. 

verb
  • To be the first batter of an inning. 

  • To be the first of any set, especially the first person in a group to speak; to launch or begin something by speaking. 

  • Used other than figuratively or idiomatically: see lead, off. 

How often have the words first base and lead off occurred in a corpus of books? (source: Google Ngram Viewer )