clobber vs gain mastery over

clobber

verb
  • To hit or bash severely; to seriously harm or damage. 

  • To overwrite (data) or override (an assignment of a value), often unintentionally or unexpectedly. 

noun
  • A thumping or beating. 

  • A bash on say the head, typically with a tool or object rather than with fists. 

  • Clothing; clothes. 

  • A paste used by shoemakers to hide the cracks in leather. 

  • Equipment. 

intj
  • to beat (someone) severely 

gain mastery over

How often have the words clobber and gain mastery over occurred in a corpus of books? (source: Google Ngram Viewer )