Riichi Mahjong · Closed 1 / open 1

Tanyao (All Simples) in Riichi Mahjong: Rules, Open Tanyao and Odds

In riichi mahjong, Tanyao (all simples) is worth 1 han: all 14 tiles — in hand and in called sets — are number tiles from 2 to 8, with no 1s, no 9s and no honors. It's simple, it fits both sequences and triplets, and on this site it also counts after a call by default (kuitan, "open tanyao"). It's one of the first yaku beginners learn and one of the most common wins.

The rules for Tanyao

• All 14 tiles are numbers 2–8: tiles in hand, called sets and the pair
• No terminals or honors: no 1 or 9, no winds, no dragons
• Sequences, triplets or seven pairs are all fine
• Calling: allowed by default here (kuitan) — 1 han closed, 1 han open

How Tanyao is scored

The yaku, han, fu and points below are computed live by the same scoring code the game uses.

Common combinations:

How it relates to other yaku

• Pinfu, riichi: tanyao hands are full of sequences and two-sided waits, so riichi-pinfu-tanyao is the classic combo.
• Sanshoku, iipeikou, chiitoitsu: as long as they use only 2–8, they all stack with tanyao.
• Toitoi: four triplets of 2–8 are tanyao too.
• Chanta, junchan, honroutou: the exact opposite — every set needs a terminal or honor — so they never combine with tanyao.

Tanyao odds

How many simples you start with

84 of the 136 tiles are numbers 2–8, about 60%. In a 13-tile starting hand you have 10 or more simples about 19% of the time, and 11 or more about 6.4%.

Source: 1,000,000 random 13-tile deals.

In normal play

Tanyao is one of the most common yaku. When the computers on this site play normally, tanyao is part of 19% of all wins; 76% of those were open (kuitan), and tanyao wins average 5,000 points.

Source: 40,000 computer hands on this site (all four at normal level), 33,226 wins. A win usually has several yaku, so the shares add up to more than 100%.

Is it worth forcing Tanyao?

We let computers play on this site's table: in every hand, the player with the most simples had to go for tanyao — discard terminals and honors first, call only 2–8 tiles, no riichi, and no win without tanyao — while the other three played normally. Then we compared the average result with the same starting hands played normally.

Source: computer play on this site. In each of 24,000 hands the seat with the best start forced Tanyao (no riichi, no other win); the other three played normally at normal level. Points are the hand’s gain or loss, including riichi sticks.

The result is clear: forcing tanyao does worse than normal play in every group.

• With 11 or more simples, forcing it works about 35% of the time and averages +268; the same starts played normally average +944.
• With 12 or more, success rises to 40% and the result to +653, still well below +1,470 for normal play.
• Finished hands averaged 2.2 han and 3,800 points after 11.5 discards — mostly cheap open tanyao with a dora or two.
• Normal play already wins with tanyao all the time; forcing it only adds restrictions — no riichi, breaking up terminal and honor pairs, no other wins — so it costs points.

Which hands suit Tanyao

• Few terminals and honors: with three or fewer in your start, just cut them first.
• Isolated honors: lone honors and 1s or 9s are tiles you'd cut anyway; once they're gone you're close to tanyao.
• You need a fast win: open tanyao lets you call, so it's a strong tool to win first — but at 1 han it's cheap.
• It works closed too: when there's no rush, tanyao with riichi and pinfu is worth far more than open tanyao.

When not to: if the 1s, 9s or honors you hold are pairs that could be a value set or your pair, throwing them away just slows you down. To try it yourself, open a table of free online riichi mahjong — the lobby also lets you switch open tanyao on or off.

Tanyao in other mahjong styles

Chinese Official (Guobiao) has "All Simples" for 2 fan (Guobiao fan table). Taiwanese and Hong Kong mahjong have no matching hand.

FAQ

How many han is Tanyao?

1 han. With this site's default rules it's still 1 han after a call (kuitan).

Can you call for Tanyao?

Yes, by default (open tanyao, same as Mahjong Soul and Tenhou). If you turn open tanyao off in the lobby, tanyao only counts for closed hands.

Can Chiitoitsu be Tanyao?

Yes. If all seven pairs are 2–8, it's chiitoitsu plus tanyao.

Related yaku

Pinfu 1 han（closed only） Four sequences, a non-value pair and a two-sided wait — closed only, 1 han. Waits, 20 vs 30 fu, common combos. Riichi 1 han（closed only） Declare it with a closed tenpai hand for 1 han: requirements, the rules after riichi, ippatsu and ura dora, win rate and average result. Sanshoku Closed 2 / open 1 The same sequence in all three suits — 2 han closed, 1 open. Examples, common combos and how to spot a sanshoku chance.