head-to-head vs time trial

head-to-head

adv
  • Directly, one-to-one. 

  • Facing one another. 

adj
  • Direct, one-to-one. 

time trial

noun
  • An unpaced race in which riders or teams leaving at regular intervals are timed over a preset course or distance, the winner being the rider or team to finish in the fastest time. 

  • Any competitive event in which competitors are timed rather than racing against each other. 

  • A mode in which the main goal is to complete levels—or, in some cases, the entire game—as quickly as possible; a time attack. 

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