by a wide margin vs rather

by a wide margin

adv

  • Synonym of by far 

rather

verb

  • To prefer; to prefer to. 

adv

  • Used to introduce a contradiction; on the contrary. 

  • Somewhat, fairly. 

  • Introducing a qualification or clarification; more precisely. (Now usually preceded by or.) 

  • Used to specify a choice or preference; preferably, in preference to. (Now usually followed by than) 

How often have the words by a wide margin and rather occurred in a corpus of books? (source: Google Ngram Viewer )