emulation vs tug of war

emulation

noun
  • The endeavor or desire to equal or excel someone else in qualities or actions. 

  • Execution of a program or other software designed for a different system, by simulating parts of the other system. 

tug of war

noun
  • 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. 

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

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