as a rule vs basically

as a rule

adv
  • In general; most often. 

basically

adv
  • mostly; generally; for the most part 

  • in a fundamental, essential or basic manner 

  • used to refer to the most important or fundamental point the speaker is making; sometimes tending towards a meaningless filler word 

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