off the mark vs on course

off the mark

prep
  • Making a start (generally in comparison to others). 

  • Inaccurate; not correct or appropriate. 

on course

prep
  • Following the intended route. 

  • Likely to happen or to undergo something. 

  • Proceeding smoothly as planned. 

How often have the words off the mark and on course occurred in a corpus of books? (source: Google Ngram Viewer )