bush league vs inexpert

bush league

adj
  • Amateurish, unprofessional, unpolished, juvenile. 

  • Of inferior quality. 

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

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

inexpert

adj
  • Inept or unskilled; not of expert ability or quality. 

noun
  • An inept or unskilled person. 

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