strength vs strong point

strength

noun
  • The quality or degree of being strong. 

  • The intensity of a force or power; potency. 

  • The strongest part of something; that on which confidence or reliance is based. 

  • A positive attribute. 

strong point

noun
  • A characteristic or ability at which one particularly excels. 

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