The Pareto Principle–also known at the 80-20 Rule, the Vital Few or the Principle of Factor Sparsity–states that 80% of the effects come from 20% of the causes.
In your job search, you want to be one of the amazingly great . . . the vital few. You want to demonstrate that you are one of the 20% who will achieve the 80%.
Everything you do–your approach, your resume, your conversations, your manner of speech, and the way you dress for the interview–has to be top-notch. You have to demonstrate that you are the best candidate for the company. If you are not, you will not get hired.