Hong Kong Versus Japanese Mahjong

As of yesterday, the McGill Students' Mahjong Club is an officially recognized club in the SSMU organization! Congratulations to us!

I'm honestly unsure what kind of mahjong is the most popular in North America. Though I would immediately assume that Americans commonly play American Style mahjong (which is thing that we will hopefully never play, since it barely even qualifies as mahjong), the game is not very popular outside of older people (and for whatever reason, specifically old Jewish women). On the other hand, the biggest source of exposure to the game in North America likely comes from Japanese anime and manga, which obviously play using Japanese Riichi style rules.

Japanese Riichi mahjong is a much more defensive game than our Hong Kong Old Style games, where in pro matches online, up to 70% of hands end in a draw, and ~30% of those draws end with no players waiting for their winning tile (known as being in 'tenpai' in Japanese). Let's look at how these games are different in order to understand them better.

1. No bonus tiles
Japanese Riichi mahjong sets come with four flower tiles and no season tiles (Instead, they come with four red tiles, two red 5-characters, a red 5-bamboo, and a red 5-dots). That being said, it is impossible for those flower tiles to be included in the wall in Japanese style. Flower tiles directly contradict the most commonly used rules of Japanese Riichi mahjong, and therefore are never used in any way.

2. The 'dead wall'
After you roll the dice, split the wall, and draw your hands, take the last 14 tiles in the wall and make a gap to separate them from the rest of the wall. These 14 tiles are the 'dead wall', and with the exception of replacement tiles from gongs, are never drawn. That means that you never know exactly what tiles are left to be drawn, and you might be waiting on a tile that's buried in the dead wall, never to be seen. Also, the dead wall is always exactly 14 tiles, so every time a gong is made, the last tile of the live wall joins the dead wall to make up for your replacement tile.

Fun fact! In Japanese, the dead wall is called the 'king's tiles'!

3. Dora tiles
So, you've separated the dead wall successfully. Now, take the third tile from the end and flip it over. This tile is the 'dora indicator', and is used to show you what the 'dora' tiles are. For example, if the dora indicator is 3-dots, the dora is 4-dots. If the indicator is 7-bamboo, the dora is 8-bamboo. If the indicator is 9-characters, the dora tile wraps back around to 1-characters. Wind tiles follow the normal pattern of east-south-west-north-East, and dragon tiles fortunately follow alphabetically, green-red-white-green.

Every dora tile in your hand is worth one faan, but cannot contribute to Japanese Riichi mahjong's one faan minimum. In addition, if you're playing with those red 5 tiles mentioned earlier, each one of those is also a dora tile.

Examples of dora tiles and dora indicators. Image taken from yakuza.wikia.com

4. Gong Dora
Every time someone makes a gong, flip over the tile next to the dora (not on the same side as the four replacement tiles). This tile is a Gong Dora indicator (known in Japanese as a Kan Dora indicator), and just increases the amount of dora in play. Aside from only appearing when a gong is made, they are functionally identical to the regular dora tiles. Because of this though, a single tile can be worth multiple fan through dora indicators.

In an extreme example, if three gongs were made and all four dora indicators were the 4-dots, and your hand had four copies of the 5-dots, each of those tiles would be worth 4 fan for a total of 16 fan (And if you were playing with the red 5 tiles, two of them would be worth 5 fan for a total of 18 fan).
As you can imagine, scoring counted limit hands is much easier in Japanese Riichi mahjong thanks to dora tiles.

5. Scoring Fu
Oh god, here's where it gets complicated. There are four types of scoring terms in Japanese Riichi mahjong. 'Yaku' (which are Seven Pairs, All Pungs, Rob a Gong, etc.), 'Faan', 'Points', and 'Fu'. Fu are like mini-faan that contribute to calculating the final score. Where 'All Pungs' would be worth 2 faan in Japanese Riichi style and a dora tile would be worth 1 faan, fu is calculated totally differently, and does not need to be counted if you score 5 faan or more, or if your hand is Seven Pairs (which is automatically worth 25 fu).

• If you win, your hand is worth 20 fu immediately.
• If your hand is concealed and you won by discard, add 10 fu.
• If you win by self-pick, whether your hand is concealed or not, add 2 fu.
• If your hand is only waiting on one tile (ex: a 1-2 characters wait for the 3-characters, a 4-6 dots wait for a 5-dots, or a wait to pair the last tile in your hand), add 2 fu.
• If your hand's pair is a pair of dragon tiles, your seat wind, or the round wind, add 2 fu.
• For every pung in your hand, add 2 fu.
• Double that fu if it's a pung of honor or terminal tiles.
• Double that fu if it's a concealed pung (just like the Four Concealed Pungs limit hand, if you claim the final tile as a discard, the pung counts as 'open' even if the hand itself is concealed).
• Quadruple that fu if it's a gong instead of a pung.
• So a closed gong of honor tiles is 2 x 2 x 2 x 4 = 32 fu, and an open pung of honor tiles is 2 x 2 = 4 fu.
• If your hand is open and scores only 20 fu, add 2 fu.
• Round the fu up to the nearest 10. A hand worth 22 fu counts as 30 fu.

6. General Scoring
So now you have your fu and your faan, how do you calculate score? Well, in Japanese Riichi mahjong, all players start with 25000 points, and if anyone drops below 0 points, the game immediately ends. If your hand has four or less fan, the formula for calculating its worth is:

base points = fu x 2^(2 + faan)

So a hand worth 30 fu and 2 faan is worth 30 x 2^(2+2) = 30 x 2^4 = 30 x 16 = 480 points! It's far less complicated to calculate than it seems, but there are charts to do the calculations if you prefer. Since your base points double for every faan you score, your hand could be worth an insurmountable sum. To cap this:

• Any hand worth 5 faan automatically scores 2000 base points.
• Any hand worth 6 or 7 faan scores 3000 base points.
• Any hand worth 8-10 faan scores 4000 base points.
• Any hand worth 11 or 12 faan scores 6000 base points.
• A hand worth 13+ faan or a limit hand scores 8000 base points.

These make calculations much easier! Once you have the base points counted, there's only a few more things to consider. If you are the dealer, double your basic points. If you win by self-pick, all three players pay you the (doubled) basic points, rounded up to the next 100. If you win by discard, that player pays you triple the (already doubled) basic points rounded up.

If you are not the dealer and you win by discard, the discarding player pays you quadruple the basic points rounded up. If you win by self-pick, the dealer pays you double the basic points rounded, and the other two players simply pay you the basic points rounded.

Fu and fan scoring table. Image taken from http://www.osamuko.com

Every time the dealer wins a hand or the hand ends in a draw, the next hand is worth an extra 300 points (So if the dealer won four hands in a row, the fifth hand would be worth an extra 4 x 300 = 1200 points).

7. Furiten
'Furiten', often translated as 'sacred discard' is a big part of Japanese Riichi style rules. The four players all have their own discard piles, and anytime an open meld is made, you must rotate a tile in the meld to show who it came from (e.g., If I call pung on a 4-dots from the player across from me, I rotate the middle tile of that open pung. If I call chow on a 2-bamboo, I rotate the 2-bamboo and place if to the left of that open chow to show that it came from the player to my left). This way, you can tell what each player discarded at a glance.

If any of your potential winning tiles are in your discards, even if that tile would mean your hand is worth 0 faan, you are not allowed to win off of a discard of any tile! For an example, imagine the only tiles left in your hand are a pair of green dragons and a pair of 1-dots. Even though you need a green dragon to complete a one faan minimum hand, you are forbidden from winning off a discard if there is a 1-dot already in your discards. Instead, you have to hope to draw the green dragon yourself, or change your hand to remove the 1-dots from it.

8. Riichi
Japanese Riichi mahjong is called 'riichi mahjong' because of this rule. The most common fan in Japanese Riichi mahjong is 'Riichi'! If you hand is fully concealed and waiting on at least one winning tile, you can declare riichi. You bet 1000 points that your hand will win first! From then on, you must discard every tile you draw until you draw your own winning tile or until another player discards it. If you win, you get your 1000 points back, but if someone else wins first, they take those points!

The main upside to riichi, aside from the extra faan, is exclusive access to the Under Dora tiles. If you declared reach and won, flip over the tiles underneath the dora indicator and revealed gong dora indicators. All of these tiles count as more dora indicators for your winning hand, so your hand's value can jump up unexpectedly!

9. The Rounds and Draws
Japanese Riichi mahjong only plays East and South rounds traditionally. In addition, there are six ways for a hand to end in a draw.

Exhaustive Draw: There are no more tiles left, aside from the dead wall. All players who are waiting for a winning tile reveal their hands. Any player who is not waiting pays a penalty. If three players are waiting, the other player pays them each 1000 points. If two players are, the other players pay them 1500 points. And if only one player is waiting, all three players pay him 1000 points (So no matter how many people are waiting, except 0 or all 4 players, 3000 points will be exchanged in total).

Abortive Draws

• If on your first turn you have at least 9 terminal or honor tiles, and no one has made an open meld or concealed gong yet, you may declare the hand a draw.
• If all four players discard the same wind tile as their first discard (without any concealed gongs being made), the hand is a draw.
• If four gongs are made by one person, anyone else who makes a gong ends the hand in a draw. If the four gongs are made by more than one person, the hand is immediately declared a draw.
• If all four players declare riichi, the hand is a draw.
• If all three other players try to win off of the same discarded tile, no one wins it and the hand is a draw.

10. Double Limit Hands
In Japanese Riichi mahjong, some limit hands are inherently worth twice the limit on their own. Generally, they're all rarer versions of other limit hands.

• Big Four Winds (Compared to Little Four Winds)
• Pair Wait on Four Concealed Pungs (Compared to normal wait on Four Concealed Pungs)
• 13-Way Thirteen Orphans Wait (Compared to normal wait on Thirteen Orphans)
• Pure Nine Gates (Compared to normal wait on Nine Gates)
• Seven Pairs All Honors (Compared to normal All Honors)