even if vs if only

even if

conj
  • Even though 

  • Regardless of whether; irrespective of (something happening or being the case). 

if only

conj
  • Even if for no other reason than; only just. 

  • Used other than figuratively or idiomatically: see if, only. 

  • I wish that; signifies a wish or desire for the present or the future. 

  • I wish that; signifies a regret about an action in the past. 

How often have the words even if and if only occurred in a corpus of books? (source: Google Ngram Viewer )