coin toss vs toss-up

coin toss

noun
  • A particular instance where a coin is launched in the air, and whichever side that it lands on finalises a decision. 

  • An uncertain selection between two outcomes of similar likelihood, or between two objects of similar quality. 

toss-up

noun
  • The toss of a coin used to decide some issue. 

  • A decision in which neither choice is clearly favorable or unfavorable, or for which the outcome does not matter. 

  • Either of two outcomes that are equally likely. 

How often have the words coin toss and toss-up occurred in a corpus of books? (source: Google Ngram Viewer )