Various ones – including kipper now and again (Hi Zoolander :)). One bridge forum I post on (bbo) is interesting because it’s one of those internet forums that have genuine experts as active posters, so the casual player (me) can interact with the absolute top men of the game. The signal to noise quality of posts is amazingly high for the internet.
It’s a bit like posting on here ‘any tips for setting up the rear shock – what works for you?’ and having Gee Atherton and Steve Peat weigh in with some advice. Plus a complete absence of biscuit-ersed ‘who cares just enjoy yourself’ type posts.
Ironically, this can be a little unhelpful as true experts are often playing a different game to us amateurs. But it’s still very cool to interact and hear what they think.