A new learner here; just started playing a few weeks ago. I have a friend who lives in another state and is recovering from surgery; she asked me if I would learn Mah Jongg and play online with her to help pass the time. She knew it would hook me. But just had to give you, a fellow math/statistics nerd, a shoutout! I've played backgammon since high school (*cough* more than 40 years ago) and it's very similar. The dice make it a game in which luck is a factor but strategy plus knowledge of math/statistics will give the informed player a huge advantage. Thanks for the tips here, btw. I realized very quickly that the concept of Mah Jongg is quite simple . . . but becoming very familiar with the tiles and then learning the hands is critical. Been playing solo online -- and making a concerted effort to avoid repeated the same hands/categories so I can get familiar with the entire card. Already a little nervous about having to switch to a new card for 2023.
I think you can really know the card, pick a hand that you have a good start for, and still lose. Of course, if you play defensively, you can stop someone else from winning. So I'm unsure of the percentage, but luck is pretty high.