The greatest minds of our time

[Brian Towers]

surely most people who really excel at something are rarely great at something else? Sticking with chess, Botwinnik was talented elsewhere.

Very much depends on what you mean by "excel" and "great". If you mean be world champion or Olympic medal standard then of course, the level of dedication makes it very difficult to achieve that level in more than one arena although it is still possible. If you just mean be in the top few percent, as perhaps your Botvinnik comment suggests, then I think it is commonplace and probably many members of this forum could confirm from their own personal experience.