second string vs sufficient

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. 

sufficient

adj
  • Possessing adequate talents or accomplishments; of competent power or ability; qualified; fit. 

  • Of a type or kind that suffices, that satisfies requirements or needs. 

det
  • A quantity (of something) that is as large as is needed. 

  • An adequate quantity of; enough. 

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