I think you'll find that if you set an absolute bar on most skills you'll end up with zero people above the bar in the past and a growing percentage of people above it in the future. The first person to run a four-minute mile was Roger Bannister in 1954. Now, that achievement is basically table stakes for college-level competitors. Similar effects can be observed in chess, piano performance, and just about any other activity you can measure. Making "first-rate" an absolute bar results in all sorts of crazy answers to the questions "who is first-rate now" and "who was first-rate 70 years ago". If you set the bar such that only the top 10 players of this year cut it, neither Bobby Fischer nor Michael Jordan would be first-rate.