Chess is played by hundreds of millions people [sic] worldwide (according to Yougov, the British market research firm)Not so much "according to YouGov", more "according to Dylan Loeb McClain", who made the claim writing the other day for AGON. (Or, if you prefer, for Ilya Merenzon.)
OK, it's not the full 605 million, but I'm going to include it in our series, because it's still a ludicrous estimate - and one just as specious, since, as regular readers know, it's not "according to YouGov" at all.
It's just another made-up, and not made up by them.
[Thanks to our informant]
[605 million index]