duel vs shootout

duel

noun
  • Historically, the wager of battle (judicial combat). 

  • Arranged, regular combat between two private persons, often over a matter of honor. 

  • Any battle or struggle between two contending persons, forces, groups, or ideas. 

verb
  • To engage in a battle. 

shootout

noun
  • A decisive battle, especially a gunfight. 

  • A series of penalty shots during which a tied game is resolved. 

  • A multitable poker tournament in which only the last player on a table goes on to the next. 

  • A match in which both teams score highly. 

  • A penalty shootout. 

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