A better sentence should give the impression that, by way of analogy, some basketball players are NBA players.
This analogy seems like a good way of explaining it. Saying (about forecasting ability) that some people are superforecasters is similar to saying (about basketball ability) that some people are NBA players or saying (about chess ability) that some people are Grandmasters. If you understand in detail the meaning of any one of these claims (or a similar claim about another domain besides forecasting/basketball/chess), then most of what you could say about that claim would port over pretty straightforwardly to the other claims.
This analogy seems like a good way of explaining it. Saying (about forecasting ability) that some people are superforecasters is similar to saying (about basketball ability) that some people are NBA players or saying (about chess ability) that some people are Grandmasters. If you understand in detail the meaning of any one of these claims (or a similar claim about another domain besides forecasting/basketball/chess), then most of what you could say about that claim would port over pretty straightforwardly to the other claims.