A spanish group won roulettes across european casinos. Their approach was different: they analyzed each individual roulette to find little differences in frequencies of each number. I.e., they profitted on the imperfections of every individual roulettes.
Their leader was a relatively known film director, writer and tv host . He wrote a book about it and someone made a movie about them.
After those roulette campaigns, he, allegedly, was successful making money with online poker.