head-to-head vs skirmish

head-to-head

adj
  • Direct, one-to-one. 

adv
  • Directly, one-to-one. 

  • Facing one another. 

skirmish

noun
  • A brief battle between small groups, usually part of a longer or larger battle or war. 

  • Any minor dispute. 

  • A type of outdoor military style game using paintball or similar weapons. 

verb
  • To engage in a minor battle or dispute 

How often have the words head-to-head and skirmish occurred in a corpus of books? (source: Google Ngram Viewer )