assistant vs second string

assistant

adj
  • Helping; lending aid or support; auxiliary. 

  • Having a subordinate or auxiliary position. 

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

  • Sales assistant. 

  • A person who assists or helps someone else. 

second string

noun
  • A unit of players which is considered to have a secondary level of talent and which usually plays after the first string. 

adj
  • Not as good; of a lower quality or condition. 

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