What is the most difficult variant of Mahjong?

If you’re talking about the Mahjong that Asian people play, then I think Taiwanese Mahjong is very difficult. I normally play Cantonese Mahjong, and there’s maybe 10–20 variations on how you can win. But playing Taiwanese Mahjong a few times, it seems like there’s hundreds of variations on how you can win. Counting the points is also very difficult because there’s so many variations. Once you get the hang of it, it’s super fun to play because you can win really big.