hitting vs slugging

hitting

noun
  • The batter's hitting improved with practice. 

  • A series of hits or blows directed at a person or object. 

slugging

noun
  • The act of hitting a ball hard; slogging. 

  • The practice of smothering one's face with vaseline in order to moisturize it. 

  • A blow or blows with the fist; a beating. 

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