How do you define best, and once you do, how much better than second best are they? What if the best person asks for several million dollars per year (an unreasonably high number as I write this), but the second will accept for $200k (a reasonable number though low if they really are second best). My guess is you cannot tell the difference between the top 20% of programmers in actual day to day work, and probably couldn't tell the difference in an interview.
How do you define best, and once you do, how much better than second best are they? What if the best person asks for several million dollars per year (an unreasonably high number as I write this), but the second will accept for $200k (a reasonable number though low if they really are second best). My guess is you cannot tell the difference between the top 20% of programmers in actual day to day work, and probably couldn't tell the difference in an interview.