bush league vs minor league

bush league

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

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

adj
  • Of inferior quality. 

  • Amateurish, unprofessional, unpolished, juvenile. 

minor league

noun
  • An association of sports teams that plays at a level below the major leagues of a sport. 

adj
  • Having a quality less than the best possible. 

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