MajhongEncyclopedia

The Yaku Encyclopedia Engine is a meticulously curated reference application that systematically collects and contrasts how Mahjong yaku — the named winning hands — are defined and scored across the four most influential mahjong schools: Japanese Riichi, MCR (Mahjong Competition Rules / International), Hong Kong Old Style, and Taiwanese 16-tile mahjong.

Each yaku entry includes its English name, romaji and kanji, a verbal definition, a representative example hand, the structural category it belongs to, its difficulty and rarity profiles, a probability estimate based on historical hand records, and a cross-school value mapping showing how that hand is recognized (or not) and scored in each school. A built-in rarity evaluation algorithm consumes hand parameters and produces a normalized rarity coefficient — useful for analytical studies and ranking exercises.

This is a study tool. It contains no gambling functionality, no real-money mechanics, no slot machines, no simulated wagering. It is intended for hobbyists, students, teachers, and competitive players who want a single English reference that makes the long-fragmented yaku landscape tractable.