Taiwanese Mahjong · 8 tai

Pure One Suit (Qing Yi Se) in Taiwanese Mahjong: Tai, Examples and Odds

In Taiwanese mahjong, Pure One Suit (清一色, qing yi se) is worth 8 tai: when you win, the whole hand — the tiles in your hand and every claimed or kong set — is from just one suit (characters, dots or bamboo), with no honor tiles at all.

The rules for Pure One Suit

• All 17 tiles are one suit: all characters, all dots or all bamboo
• No honors (winds or dragons); with honors it's Half One Suit instead
• Chows, pungs and kongs are all allowed — the hand doesn't need to be concealed
• Flowers don't affect it; they score separately as seat flowers or flower sets

Pure One Suit vs Half One Suit

They are one family and only the highest counts: Pure One Suit never adds Half One Suit.

How Pure One Suit waits

Tiles of one suit connect, so a ready hand often waits on many tiles at once — that's what makes it easier to finish once you are close. This hand wins on every tile from 1 to 9 characters:

The flip side: a player going for Pure One Suit discards almost nothing from that suit, so the others can read it from the discards and hold those tiles.

How Pure One Suit is scored

The tai below are computed live by the same scoring code the game uses (dealer and dealer-streak tai are added on top).

Common combinations:

How it relates to other hands

• Half One Suit: one suit plus honors, 4 tai. If you're halfway to Pure One Suit but still hold an honor pair, switching to Half One Suit is often faster.
• All Pungs: all five sets are pungs; stacks with Pure One Suit for 12 tai.
• Ping Hu: five chows, no honors, no flowers, two-sided wait, won on a discard — another 2 tai. Pure One Suit has no honors anyway, so a hand full of runs can pick it up.
• Concealed pungs: three or more self-drawn pungs score extra and stack with Pure One Suit.

Pure One Suit odds

How many tiles of one suit you start with

Pure One Suit needs all 17 tiles from one suit, and each suit has only 36 tiles. In a 16-tile opening hand, the strongest suit has 9 or more tiles about 2.1% of the time, and 10 or more only 0.39%.

Source: 1,000,000 random 16-tile deals (flowers already replaced).

Is it worth forcing Pure One Suit?

We let computers play on this site's table: in every hand, the player with the most tiles of one suit had to go for Pure One Suit — discard other suits and honors first, only claim that suit, never win with anything else — while the other three played normally. Then we compared the average result with the same opening hands played normally.

Source: computer play on this site. In each of 20,000 hands the seat with the best start forced Pure one suit (清一色); the other three played normally. Money at 100 base + 20 per tai, dealer tai included.

The verdict is clear: at a table this fast, forcing Pure One Suit loses money in every group.

• Even with 10 or more tiles of one suit, forcing it only works 2.4% of the time, for an average result of −56; the same starts played normally average +40.
• Pure One Suit needs all 17 tiles in one suit. When it did work, it took 11.1 draws on average — and by then someone else has usually won: with 10+ tiles, 90% of hands ended with another player's win.
• A finished Pure One Suit averaged 9.5 tai, but it happens too rarely to make up for the hands you lose.
• When the computers play normally, Pure One Suit is 0% of all wins: fast play almost never stumbles into it.

Which hands suit Pure One Suit

• Lots of one suit in the opening hand: by far the most important factor — see the numbers above.
• Tiles that connect: with the same count, adjacent pairs of tiles beat scattered ones, because they let you chow.
• Claiming is allowed: Pure One Suit doesn't need a concealed hand, so chow that suit from the player on your left and save several turns.
• Others will defend: two exposed sets of one suit and none of it in your discards tell everyone what you're doing, and they'll keep that suit.

When to give up: less than half the wall is left and you still hold three or more tiles from other suits, or someone is clearly ready while you're far away. Switch to Half One Suit, or go back to playing fast. To try it yourself, open a table of online Taiwanese mahjong — the computers play with you and count the tai for you.

Pure One Suit in other mahjong styles

Pure One Suit is a big hand everywhere, but scores differently:

• Japanese mahjong ("Chinitsu"): 6 han concealed, 5 han open (Chinitsu in Japanese mahjong)
• Hong Kong mahjong: 7 fan (Pure One Suit in Hong Kong mahjong)
• Sichuan mahjong: 2 fan (Pure One Suit in Sichuan mahjong)
• Chinese Official (Guobiao, "Full Flush"): 24 fan (Full Flush in Guobiao mahjong)

FAQ

How many tai is Pure One Suit?

In Taiwanese mahjong Pure One Suit is worth 8 tai. It stacks with All Pungs, concealed hand, concealed self-draw, Ping Hu, concealed pungs and more.

Can Pure One Suit have honor tiles?

No. With honors it's Half One Suit, 4 tai; a hand of only honors is All Honors, 16 tai.

Can you chow or pung in Pure One Suit?

Yes. Taiwanese Pure One Suit doesn't require a concealed hand; claimed sets just have to be the same suit.

How many tai is Pure One Suit with All Pungs?

Pure One Suit 8 plus All Pungs 4, 12 tai in total — more if three or more of the pungs are concealed.

Do flowers affect Pure One Suit?

No. Flowers aren't part of the 17 tiles; your own seat flower scores a separate 1 tai.

Related hands

All Pungs 4 tai Five pungs and a pair, no chows allowed — 4 tai. Examples, scoring combos and how many pairs you need to go for it. Half One Suit 4 tai One suit plus honors — a 4-tai hand. Examples, Half One Suit vs Pure One Suit, and how concentrated your start must be. Ping Hu 2 tai Five chows, no honors, no flowers, two-sided wait, no self-draw — a 2-tai hand. Checklist, common mistakes and odds.