assistant vs third string

assistant

noun
  • A software tool that provides assistance in some task, a wizard program. 

  • Sales assistant. 

  • A person who assists or helps someone else. 

adj
  • Helping; lending aid or support; auxiliary. 

  • Having a subordinate or auxiliary position. 

third string

noun
  • A unit of players that plays behind the first and second strings; a junior varsity team. 

adj
  • Of a decidedly lower quality or condition. 

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