Seven Pairs

Seven Pairs (chiitoitsu in Japanese Riichi) is a special winning structure that abandons the usual four-melds-plus-a-pair framework: the hand is instead made of seven distinct pairs, totaling fourteen tiles. It is one of only two standard exceptions to the meld-based shape (the other being thirteen orphans), and because it is built from pairs alone it cannot contain any chow or pung.

The rules on what counts vary. In Riichi, chiitoitsu is a 2-han, closed-only yaku and is fixed at exactly 25 fu; critically, the seven pairs must all be different — you cannot use two identical pairs (four of the same tile) to satisfy two of the seven, even though four-of-a-kind is otherwise legal tile-wise. It combines well with tanyao or honitsu and forms the basis of the rare daburu riichi/suuankou-adjacent value hands, though as a closed hand it must be hidden until the win. Chinese MCR scores Seven Pairs at 24 points, and Hong Kong rules typically award it a flat faan value; some Chinese rules permit four-of-a-kind as two pairs while Riichi does not.

A concrete winning hand might be 1m1m, 4m4m, 2p2p, 9p9p, 3s3s, 6s6s, and East-East — seven separate pairs across suits and honors. The wait is always a single-tile pair wait (tanki-style), since the hand needs one final tile to complete the seventh pair, which makes seven pairs comparatively easy to read defensively but flexible to steer. A frequent confusion is mixing it with all pungs: seven pairs is never melded and never declared open, whereas all pungs is triplet-based and can be open. Beginners also forget the no-duplicate-pair rule in Riichi, which can invalidate an apparently complete hand.