mastermind vs researcher

mastermind

noun
  • A person with an extraordinary intellect or skill that is markedly superior to his or her peers. 

  • A person responsible for the highest level of planning and execution of a major operation. 

verb
  • To act in the role of mastermind. 

researcher

noun
  • One who researches. 

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