have a handle on vs self-control

have a handle on

verb

  • To be in control of, to have power over. 

  • To understand or grasp. 

self-control

verb

  • To control oneself or itself. 

noun

  • The ability to control one's desires and impulses; willpower. 

How often have the words have a handle on and self-control occurred in a corpus of books? (source: Google Ngram Viewer )