I - really - wanted to learn mahjong, even though it's a time sink, sometimes I could log in just to play a match.

But.

The rules are presented in texts that are way too confusing to read, like the OP says. The weird asian language names "pon" "richii" etc doesn't help a western player at all too, but that's the lesser of things.

I really wanted a "tutorial" table, in which you play and learn the rules on the fly via tooltips with screen pointers.