sure bet vs uncertainty

sure bet

noun
  • Synonym of safe bet, good bet, fair bet 

uncertainty

noun
  • Doubt; the condition of being uncertain or without conviction. 

  • A parameter that measures the dispersion of a range of measured values. 

  • Something uncertain or ambiguous. 

How often have the words sure bet and uncertainty occurred in a corpus of books? (source: Google Ngram Viewer )