Chess is often regarded by smart people as a great way to unwind, while still mentally challenging themselves. Yet this is not a view universally held. The great physicist Arnold Sommerfeld, for example, discouraged his students from it, as Werner Heisenberg told Thomas Kuhn in a 1963 interview:

[Sommerfeld] had strong views about how young people should behave. So he was, in that way, very old-fashioned.For instance, I recall that Pauli — I don’t know for sure whether it was Pauli — was always a bit late in the Institute in the morning. He didn’t come before 12 o’clock — he would work at night. And then Sommerfeld once asked Pauli why he came so late and Pauli said that he worked so well at night. And then Sommerfeld told him, “Well, this is a mistake. You do not work well at night; you work very much better early in the morning. So I think tomorrow morning you will come at eight o’clock to the Institute.” So Pauli would try to come at eight o’clock.

Sommerfeld would always have very definite opinions as to what people should do and should not do. And so also about this game of chess. He said, “Well, you shouldn’t waste your time by playing chess. If you do have that kind of effort, then you’d better do physics; if you want to have some recreation, you can go skiing.”

The assumption that you’re likely to do your best work in the morning is one that’s pretty richly documented (though of course there are people who are genuine night owls).

The fact that Sommerfeld also recommends skiing as recreation is notable: his assumption is that physical exercise (even a somewhat mentally engaging one) is a better form of recreation than an activity that’s sedentary but mentally challenging.