criticize vs pat on the back

criticize

verb
  • To evaluate (something), assessing its merits and faults. 

  • To find fault (with something). 

pat on the back

noun
  • Praise, congratulations. 

verb
  • To praise or congratulate. 

How often have the words criticize and pat on the back occurred in a corpus of books? (source: Google Ngram Viewer )