I have heard the same thing. Someone I know smokes rarely, but he plays chess online quite often. He tells me after every time he smokes (probably just one or t

I have heard the same thing. Someone I know smokes rarely, but he plays chess online quite often. He tells me after every time he smokes (probably just one or two joints) his performance is noticeably worse for a week after. And this is from someone who just smokes maybe once a month if at all, daily smoking could impair your cognitive abilities a lot more. But then again this is all more or less anecdotes, still seems to be something about it though.