bush league vs second string

bush league

adj
  • Of inferior quality. 

  • Amateurish, unprofessional, unpolished, juvenile. 

noun
  • A professional sports association at the lower levels of minor league organization. 

  • A low-ranking or inferior level among groups, professions, organizations, etc. 

second string

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

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

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