Mahjong Notes

Shoutout to hue for recommending Japanese resources and proofreading this post. Introducing The Win Dealin Ratio Your opponent declares riichi. Do you push a dangerous tile, or fold? Some players may refer to a flowchart (push good wait with X han), or a chart of expected values (EVs) to answer this question, but I think there’s a deeper understanding to be had. What is the math underlying these charts, and how can you modify your answer if parameters such as value, dealinrate, ability to fold/maneuver, or position change? I'm going to propose a heuristic that will help you answer push fold problems in a variety of circumstances. This is a concept that I borrowed from poker and modified for riichi mahjong. It’s a concept that is so important that I think about it in every game of mahjong that I play, and one that I wish I was formally taught as a beginner. It starts with a very simple idea: if I push, what percentage of the time will I win, and what percentage of the ti