checkered vs unflecked

checkered

adj
  • Divided into squares, or into light and dark patches. 

  • Changeable; inconsistent; having variations or uncertainty; marked by many problems or failures. 

unflecked

adj
  • Not marked with flecks. 

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