faultless vs second string

faultless

adj
  • Without fault; free from defect or error. 

second string

adj
  • Not as good; of a lower quality or condition. 

noun
  • A unit of players which is considered to have a secondary level of talent and which usually plays after the first string. 

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