Hong Kong Mahjong · 7 fan
Pure One Suit (Ching Yat Sik) in Hong Kong Mahjong: Fan, Examples and Odds
In Hong Kong mahjong, Pure One Suit (清一色, ching yat sik) is worth 7 fan: 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 honour tiles at all.
Pure One Suit is already 7 fan and the limit is 10 fan, so three more fan reach the cap: add No Flowers, a concealed hand, self-draw or All Pungs and it often goes straight to the limit.
On this page
The rules for Pure One Suit
- All 14 tiles are one suit: all characters, all dots or all bamboo
- No honours (winds or dragons); with honours it's Mixed 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 (No Flowers, own flower, flower set)
Pure One Suit vs Mixed One Suit
| Hand | Suited tiles | Honours | Fan |
|---|---|---|---|
| Pure One Suit | One suit only | None | 7 fan |
| Mixed One Suit | One suit only | Some | 3 fan |
| All Honours | None | All | Limit |
They are one family and only the highest counts: Pure One Suit never adds Mixed 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 easy to finish once you are ready. The most famous example is Nine Gates:
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 fan below are computed live by the same scoring code the game uses; with no flowers you also get No Flowers for 1 fan.
Won on a discard
| All chows (平糊) | 1 |
| Pure one suit (清一色) | 7 |
| No flowers (無花) | 1 |
| Total | 9 fan |
|---|
Anything over 10 fan scores 10 (the limit).
Self-drawn
| Concealed hand (門前清) | 1 |
| Self-drawn (自摸) | 1 |
| Pure one suit (清一色) | 7 |
| No flowers (無花) | 1 |
| Total | 10 fan · Limit |
|---|
Anything over 10 fan scores 10 (the limit).
Won on a discard
| All pungs (對對糊) | 3 |
| Pure one suit (清一色) | 7 |
| No flowers (無花) | 1 |
| Total | 10 fan · Limit |
|---|
Anything over 10 fan scores 10 (the limit).
Common combinations:
| Combination | Fan |
|---|---|
| Pure One Suit | 7 fan |
| Pure One Suit + No Flowers | 8 fan |
| Pure One Suit + All Chows | 8 fan |
| Pure One Suit + concealed hand + self-draw | 9 fan |
| Pure One Suit + All Pungs | 10 fan · Limit |
| Concealed 1112345678999 + one more of the suit (Nine Gates) | Limit |
How it relates to other hands
- Mixed One Suit: one suit plus honours, 3 fan. If you're halfway to Pure One Suit but still hold an honour pair, switching to Mixed One Suit is often faster — and with an honour pung it still clears the minimum.
- All Pungs: all four sets are pungs; with Pure One Suit that's already 10 fan · Limit.
- All Chows: four chows add 1 fan. Pure One Suit has no honours anyway, so a hand full of runs picks it up easily.
- Nine Gates: a concealed one-suit hand of 1112345678999 before the win is a limit hand.
Pure One Suit odds
How many tiles of one suit you start with
Pure One Suit needs all 14 tiles from one suit, and each suit has only 36 tiles. In a 13-tile opening hand, the strongest suit has 7 or more tiles about 7.8% of the time, and 8 or more only 1.6%.
| Most tiles of one suit in the opening hand | Chance |
|---|---|
| 5+ tiles | 65% |
| 6+ tiles | 27% |
| 7+ tiles | 7.8% |
| 8+ tiles | 1.6% |
| 9+ tiles | 0.25% |
| 10+ tiles | 0.028% |
Source: 1,000,000 random 13-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 honours first, only claim that suit, never win with anything else — while the other three played normally. Then we compared how often it came off, and the average result, with the same opening hands played normally.
| Most tiles of one suit in the opening hand | Opening hands | Made it | Made it anyway, playing normally | Someone else won | Exhaustive draw | Avg. result forcing it | Avg. result playing normally |
|---|---|---|---|---|---|---|---|
| 5 or fewer | 3,668 | 4.7% | 0.027% | 71% | 24% | +1.0 | −0.2 |
| 6 | 7,220 | 9.2% | 0.18% | 68% | 23% | +8.2 | −0.1 |
| 7 | 3,803 | 17% | 0.71% | 64% | 19% | +20.5 | +1.1 |
| 8 | 1,080 | 29% | 2.1% | 57% | 15% | +41.2 | +3.3 |
| 9+ tiles | 229 | 37% | 7.5% | 55% | 8.7% | +54.4 | +11.1 |
Source: computer play on this site. In each of 16,000 hands the seat with the best start forced Pure one suit (清一色); the other three played normally (Normal level). Results in base units (3-fan minimum, 10-fan limit, half-spicy scoring, discarder pays).
The result surprises most players: under Cantonese scoring, forcing Pure One Suit pays far better than playing normally.
- With 7 or more tiles of one suit, forcing it works 20% of the time, for an average result of +26.4 base units; with the same starts played normally, the player made Pure One Suit only 1.2% of the time and averaged +1.9.
- With 8 or more it's even clearer: 30% made, averaging +43.5 against +4.6 playing normally.
- Finished hands averaged 8.1 fan after 15.1 draws. With half-spicy scoring, payouts grow fast with fan — one Pure One Suit outweighs many small wins.
- The price is speed: with 7+ tiles, 62% of hands ended with someone else's win.
- When the computers play normally, Pure One Suit is only 0.83% of all wins: our computers tend to win as soon as they reach 3 fan and rarely chase big hands.
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 Mixed One Suit, or go back to playing for a quick 3 fan. To try it yourself, open a table of online Hong Kong mahjong — the computers play with you and count the fan for you.
Pure One Suit in other mahjong styles
Pure One Suit is a big hand everywhere, but scores differently:
- Taiwanese mahjong: 8 tai (Taiwanese mahjong Pure One Suit)
- Japanese mahjong ("Chinitsu"): 6 han concealed, 5 han open (Japanese mahjong Chinitsu)
- Sichuan mahjong: 2 fan (Sichuan mahjong Pure One Suit)
- Chinese Official (Guobiao, "Full Flush"): 24 fan (Guobiao Full Flush)
FAQ
How many fan is Pure One Suit?
In Hong Kong mahjong Pure One Suit is worth 7 fan. Add No Flowers, a concealed hand, self-draw or All Pungs and it quickly reaches the 10-fan limit.
Can Pure One Suit have honour tiles?
No. With honours it's Mixed One Suit, 3 fan; a hand of only honours is All Honours, a limit hand.
Can you chow or pung in Pure One Suit?
Yes. Hong Kong Pure One Suit doesn't require a concealed hand; claimed sets just have to be the same suit.
How many fan is Pure One Suit with All Pungs?
Pure One Suit 7 fan plus All Pungs 3 fan: 10 fan · Limit.
Do flowers affect Pure One Suit?
No. Flowers aren't part of the 14 tiles; your own flower scores 1 fan each, and no flowers at all scores No Flowers 1 fan.
Related hands
Mixed One Suit 3 fan
One suit plus honours — 3 fan, enough to win by itself. Examples, the difference from Pure One Suit, combos and how many 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.
Nine Gates Limit
1112345678999 in one suit, waiting on every tile 1 to 9: the ultimate concealed one-suit hand, scored at the limit.
Try it at the table
Hong Kong Mahjong — Play classic Hong Kong (Cantonese) mahjong free in your browser against three computer opponents. 13-tile hands, flowers, 3-fan minimum, 10-fan limit and automatic fan scoring. No sign-up, works on phone and desktop.