happenstance vs horseshoe up one's ass

happenstance

noun

  • The chance or random quality of an event or circumstance. 

  • A chance or random event or circumstance. 

horseshoe up one's ass

noun

  • Exceptionally favorable personal luck. 

How often have the words happenstance and horseshoe up one's ass occurred in a corpus of books? (source: Google Ngram Viewer )