There's a whole body of research out there, but I just scratched the surface of it. Here's the first result that's coming up from a random Google search. https://psy.fsu.edu/faculty/ericsson/ericsson.exp.perf.html The references should be worth exploring, and I bet there's more recent research that expands on it as well. Here's a quote from the paper:

> In a recent review, Ericsson and Lehmann (1996) found that (1) measures of general basic capacities do not predict success in a domain, (2) the superior performance of experts is often very domain specific and transfer outside their narrow area of expertise is surprisingly limited and (3) systematic differences between experts and less proficient individuals nearly always reflect attributes acquired by the experts during their lengthy training.

I will say this for Chess or Go grandmasters: They have drive and dedication (and in some cases, compulsiveness). That alone would probably allow them to do better than the average person in another field if they had pursued that field from the get-go. Also, I'd caution you against relying on hand-picked anecdotes; I could just as easily pick out a bunch of Chess players who weren't good for anything else. You'd need broad-based statistics.

You seem to be confusing two different claims:

1. A champion Go/Chess player could retire, and jump a successful career as <Something else>. You refute 1.

2. A champion Go/Chess player could have pursued a career in <Something else> from the start and made more money. You have not refuted 2.

For an example, many physics PhDs become successful software engineers and quants, making a mid-career jump to a different field.

Thanks for the link. Well, of course I just quoted a few examples without pretending it's legitimate piece of statistics, however, there hasn't been all that many world chess champions so far (and Botvinnik, Smyslov, Euwe, Karpov, belong in that category), and thus a few PhDs or successful intellectual careers is already enough to show that something clearly sets this bunch apart from the general public. You're less likely to find a plumber or a shelf-stacker in that bus (no disrespect for people in these professions). Whatever causes that is another matter. I agree with you that drive and dedication - and not necessarily some innate talents - could be the crucial factor in this.