tug of war vs variance

tug of war

noun
  • A dispute between two parties, particularly an entrenched, back-and-forth dispute. 

  • A game or competition in which two teams pull or tug on opposite ends of a rope trying to force the other team over the line which initially marked the middle between the two teams. 

variance

noun
  • The state of differing or being in conflict. 

  • A discrepancy between two legal documents. 

  • A departure from a cause of action originally in a complaint. 

  • An official permit to do something that is ordinarily forbidden by regulations. 

  • The act of varying or the state of being variable. 

  • The number of degrees of freedom in a system. 

  • Covariance and contravariance generally. 

  • A difference between what is expected and what is observed; deviation. 

  • The second central moment in probability. 

How often have the words tug of war and variance occurred in a corpus of books? (source: Google Ngram Viewer )