Ryanmen
By Kenji Tanaka · Updated
Definition
Ryanmen is the two-sided wait, the best ordinary shape in the game: hold 4-5 and win on 3 or 6, eight live tiles against four for the inside waits. Wait width is win rate, so hand-shaping revolves around making and keeping ryanmen, and pinfu requires finishing on one. Its lone quirk: a ryanmen adds no wait fu, which is exactly why pinfu's flat 20 exists.
Ryanmen (両面)
Ryanmen is a double-sided wait pattern in mahjong, considered the strongest and most efficient waiting configuration. It occurs when you need to complete a sequence by drawing either of two different ranks, with eight tiles available to win.
The mechanics of Ryanmen
Ryanmen literally translates to “both sides” in Japanese, accurately describing how this wait functions. When you have two consecutive numbers in a sequence, such as 4-5 of the same suit, you can win by drawing either the 3 or the 6, completing either the 3-4-5 or 4-5-6 sequence respectively.
Why Ryanmen is Superior
Ryanmen is universally recognized as the optimal wait pattern because it offers the highest probability of winning. Since eight different tiles can complete your hand (four copies of the 3 and four copies of the 6 in a standard game), you have the maximum number of outs among all wait types. This statistical advantage makes ryanmen waits the target for skilled players during hand development.
Comparison with Other Waits
Unlike ryanmen, other wait patterns offer fewer winning tiles:
- Kanchan (middle wait) occurs with non-consecutive numbers like 3-5, waiting only on the 4, providing just four tiles
- Penchan (edge wait) happens at sequence boundaries like 1-2 or 8-9, waiting on only one rank and offering four tiles
- Tanki (pair wait) requires a specific tile, offering at most three winning tiles since you hold one copy yourself
The superiority of ryanmen becomes especially apparent in competitive play, where probability directly influences winning rates.
Development Strategy
Players actively work toward ryanmen waits during hand development. When choosing which tiles to discard early in a round, experienced players prioritize creating potential ryanmen patterns over other wait types. This strategic focus on ryanmen waits is fundamental to efficient mahjong play and separates casual players from competitive ones.
Example: Ryanmen in a real hand
Consider this hand development scenario:
You hold 3-4 of bamboo tiles and are considering your discards. This 3-4 combination has ryanmen potential, you can win by drawing either 2 bamboo or 5 bamboo, giving you eight possible winning tiles total. As the round progresses and you draw additional tiles, maintaining this ryanmen wait while working toward other combinations becomes a priority.
Later in the hand, if you draw a 5 bamboo, your ryanmen wait becomes stronger. You now have 3-4-5 completed and might develop new ryanmen waits with other tiles in your hand, such as 6-7, which waits on 5 or 8.
Conversely, if you draw the 2 bamboo early, you complete the 2-3-4 sequence and must develop ryanmen patterns from your remaining tiles. This demonstrates how ryanmen waits constantly shift and evolve throughout a hand.
Related Terms
Kanchan
嵌張
Kanchan is the closed wait: holding the two outer tiles of a run and needing the middle, like 3-5 waiting on 4. Four winning tiles, tied with penchan for weakest ordinary wait, and usually worth reshaping into a ryanmen when the hand allows it. Its consolation prize is 2 fu.
Penchan
辺張
Penchan is the edge wait: 1-2 needing 3, or 8-9 needing 7. Four winning tiles, one direction, the same weakness as kanchan, plus the same 2 fu consolation. It is a standard candidate to break when improving shape at iishanten, since a ryanmen accepts twice as many tiles.
Pinfu
平和
The all-sequences yaku, worth 1 han on a closed hand. Four conditions must hold: sequences only, a pair that is not a value tile, a two-sided ryanmen final wait, and no calls. Scored at a flat 20 fu when won by tsumo. Usually the first yaku beginners learn to build on purpose.