heads-up vs sharp-sighted

heads-up

adj
  • With head directly above the neck, eyes front. 

  • Alert; vigilant 

noun
  • Involving two players. (usually said when there are only two players in the table; or, when all players except two folded) 

  • A warning or call to pay attention; an advisory notice; a notice of what is to happen; a holler. 

sharp-sighted

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