Hong Kong Mahjong · 3 fan

Mixed One Suit (Wun Yat Sik) in Hong Kong Mahjong: Fan, Examples and Odds

In Hong Kong mahjong, Mixed One Suit (混一色) is worth 3 fan: when you win, every suited tile — in your hand and in your claimed chows, pungs and kongs — is from one suit only (characters, dots or bamboo), and the hand also contains honours (winds or dragons).

Cantonese tables need 3 fan to win, and Mixed One Suit is 3 fan on its own, so it needs nothing else. Honour pungs, No Flowers and self-draw pile on top, which makes it one of the most common ways to reach the minimum.

The rules for Mixed One Suit

• Suited tiles from one suit only: all characters, all dots or all bamboo
• There must be honours: as a pung or as the pair; with no honours at all it is Pure One Suit
• Chows, pungs and kongs are all allowed; the hand need not be concealed
• Flowers don't count; they score separately as No Flowers, Own Flower or Flower Set

Mixed One Suit, Pure One Suit, All Honours

They are one family, and only the highest counts: Pure One Suit never adds Mixed One Suit as well.

How Mixed One Suit is scored

The fan below are computed live by the same scoring code the game uses.

Common combinations:

How it relates to other hands

• Pure One Suit: one suit, no honours, 7 fan. If you discard all your honours on the way, Mixed One Suit turns into Pure One Suit; the other way round, if Pure One Suit is close but you still hold an honour pair, switching to Mixed One Suit is usually much faster.
• All Pungs: honours can be punged but never chowed, so Mixed One Suit often ends up as All Pungs too — 6 fan together.
• Dragon pung, Round Wind, Seat Wind: if the honour pungs are scoring honours, each adds one fan.
• Small Three Dragons: two dragon pungs and a dragon pair; with Mixed One Suit that is already 8 fan.
• Mixed Terminals: pungs of only 1s and 9s of one suit plus honours score Mixed One Suit, All Pungs and Mixed Terminals together.

Mixed One Suit odds

One suit plus honours in the opening hand

Mixed One Suit needs all 14 tiles to be from one suit or honours. In a 13-tile opening hand, the best suit plus honours comes to 9 or more tiles about 23% of the time, and 10 or more about 6.8%.

Source: 1,000,000 random 13-tile deals (flowers already replaced).

Is it worth forcing Mixed One Suit?

Same set-up as the Pure One Suit experiment: in every hand, the player with the most tiles in "best suit plus honours" had to go for Mixed One Suit — discard the other suits first, chow or pung only that suit and honours, and never win with anything less (Pure One Suit or All Honours also count) — while the other three played normally. Then we compared it with the same opening hands played normally.

Source: computer play on this site. In each of 16,000 hands the seat with the best start forced Mixed one suit (混一色); the other three played normally (Normal level). Results in base units (3-fan minimum, 10-fan limit, half-spicy scoring, discarder pays).

As with Pure One Suit, under Cantonese scoring forcing Mixed One Suit pays far better than playing normally, and you don't need a great start for it to pay.

• With 9 or more tiles of one suit plus honours, forcing it works 39% of the time, for an average of +19.3 base units; with the same starts played normally, the player made Mixed One Suit only 4.3% of the time and averaged +1.2.
• With 10 or more: 45% made, averaging +23.4 against +3.9 playing normally.
• Finished hands averaged 5.0 fan after 13.0 draws — quicker than Pure One Suit, because honours can be punged and there is a whole extra group of useful tiles.
• The cost: with 9 or more tiles, someone else still wins first in 51% of hands.
• When the computers play normally, Mixed One Suit is 6.6% of all wins, and those wins average 4.6 fan.

Which hands suit Mixed One Suit

• Plenty of one suit plus honours in the opening hand: see the table above — the more, the better it pays.
• Honour pairs: honours can only be punged, so one or two honour pairs get you close fast; dragons and your seat or round wind add fan when punged.
• Claim freely: Mixed One Suit doesn't need a concealed hand, so chow your suit from the player on your left.
• Others will notice: two exposed sets of one suit and none of that suit in your discards tell everyone what you're doing.

When to give up: less than half the wall is left and you still hold three or more off-suit tiles, or someone is clearly ready. Switch back to normal play. To try it, open a table of online Hong Kong mahjong — the computers play with you and count the fan for you.

Mixed One Suit in other mahjong styles

How much Mixed One Suit is worth varies a lot between styles:

• Taiwanese and Japanese mahjong both have it, scored differently: see the Taiwanese mahjong tai table and the Japanese mahjong yaku list
• Sichuan mahjong has no honour tiles, so there is no Mixed One Suit — only Sichuan Pure One Suit
• Chinese Official (Guobiao) mahjong has it too: see the Guobiao fan table

FAQ

How many fan is Mixed One Suit?

In Hong Kong mahjong Mixed One Suit is worth 3 fan — exactly the 3-fan minimum. Honour pungs, All Pungs or self-draw quickly take it to five or six fan and more.

Does Mixed One Suit need honour tiles?

Yes. With no honours and only one suit it is Pure One Suit, 7 fan; all honours is All Honours, a limit hand.

Can you chow or pung in Mixed One Suit?

Yes. It doesn't need a concealed hand; claimed chows, pungs and kongs are fine as long as they are all from the one suit or honours.

How many fan is Mixed One Suit with All Pungs?

Mixed One Suit 3 fan plus All Pungs 3 fan makes 6 fan; add a dragon pung and it is 7 fan.

Related hands

Pure One Suit 7 fan Every tile from a single suit — 7 fan, one step from the limit. Examples, Mixed vs Pure One Suit, and how many suited tiles you need to go for it. All Pungs 3 fan Four pungs and a pair, no chows — 3 fan, exactly enough to win. Examples, scoring combos and how many pairs you need to go for it. All Honours Limit Every tile a wind or dragon — a limit hand scored at the maximum at once, always All Pungs, and how it overlaps the three-dragon and four-wind hands.