hand off vs hand on

hand off

verb
  • to pass or transfer. 

  • to pass (the ball) to a teammate 

hand on

verb
  • To transfer (something) to someone else, especially as a replacement for oneself (such as an official office or duty); to transfer something that was originally given to oneself from someone else. 

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