Riichi Mahjong in Singapore

By Mid-August there will be a tournament that uses Jansou (Parlors) rules. The date is yet to be confirmed but it will be a 1 Sunday tournament. KJ is currently checking whether venue will be available on either of the Sundays of August.

This tournament is organised with the aim of allowing our Riichi players to be exposed to how is it like to play in a Jansou. Although the environment here is definitely a lot healthier, it is still nevertheless a good experience for players if they wish to give it a try when they are in Japan. The learning curve will be less steep. In preparation for the coming tournament, a practice session will be held to help players familiarise with the new rules. It is NOT compulsory to attend this but it is meant to be such that we have fewer blur players during the tournament.

There are many many variant Jansou rules across Japan. For this coming tournament, we will be making reference to ZOO, a very popular Jansou in Tokyo. Probably the most popular one I know as I see them everywhere in Tokyo. Just for your information, I think the most popular one in Kyoto is Marchao. (These are anecdotal evidence)

Variant Rules

Note: Any rules not mentioned above will be assumed to follow the WRC rules.

Shuugi (祝儀)

“Competing” in a Jansou context is pretty much based on how much $$$ you win or lose. Let’s call this $$$, Wallet Points (WP). If you are confused, sub the word, WP into Yen. Don’t want to have sensitive words in this post.

The most differentiating rule about Jansou rule is Shuugi. What we currently know about Mahjong is that, at the end of the game, players earn/lose WP based on the results. But Shuugi is bonus WP earned directly from players based on winning a hand. In laymen terms, its like Singapore Mahjong’s Kan payment.

You get 100WP for EACH of the following:

• Ippatsu
• Ura-Dora
• Aka-Dora (Concealed only*)

*ZOO’s old rule. The updated rule doesn’t require one to get shuugi from concealed but it makes the game extremely unbalance. This is the only exceptional rule that I strongly disagree to play with.

Example

You won a hand with Riichi Ippatsu Aka dora 1 Ura-Dora 1. You get 300 WP from each player if tsumo. If a person dealt into you for the same hand, that person pays you 300 WP. So strategically speaking for earning shuugi, one should aim for tsumo as much as possible.

You won a hand with Riichi Ura-Dora 3. You get 300 WP if ron, 900 WP if tsumo.

Exceptions

All-Star: Getting 3 aka-dora (Concealed only) gives you 500 WP)

Yakuman: Ron is 1000WP, Tsumo is 500WP all

Oka & Uma

With the current WRC rules we play with, there is no Oka. But all arcade and Jansou mahjong rules play with Oka. Oka is like a jackpot that rewards the 1st player, making 1st more attractive. It is just an additional thing to consider when calculating the final score.

Currently, if you have 50k and get 1st, you get 50 – 25 (Base Score) + 15 (WRC Uma) = 40. That’s it.

For the Jansou rule we are playing, the Oka is 20k, meaning each player has to fork out 5k into the jackpot. Using the same example, this is done by 50 – 30 + Uma. Notice that instead of minus 25, we minus 30. Meaning, you need 30k score to actually breakeven. 30k here refers to “goal”, at least 1 player must have at least 30k score to end the han-chan otherwise all players are in negative score which will not make sense.

The Uma we will be using is 20/10/-10/-20. Therefore, using the same example the score for top place is 50 – 30 (Goal) + 20 (Uma) + 20 (Oka) = +60

As for other positions, it will be their Raw score – 30 (Goal) + Uma = Final Score.

Rounding Off

Please note that all the score that has been converted to thousands, have to be rounded off but if is 0.5, it is round DOWN. I repeat, 0.5 is round DOWN. There are cases whereby there is a +- 1 rounding error, when it happens, adjust the error by forcing a round up or down on the player who get 1st or last.

Example

Above are the steps taken to calculate the final score. Based on the general rounding rule, we will notice that the last place’s score of -46.6 is supposed to round up to -47 but this will result in an outstanding of -1 if we try to tally the score. We CANNOT adjust this error by +1 to first place, because that is effectively adding points to 1st place. We can ONLY adjust the error by adjusting the rounding portion. Therefore since 1st place has already rounded up, it cannot be increased any further and decreasing it will give a total error of -2. So we force a round down on -46.6 to -46.

Note: This method currently does not have very reliable source yet. Jansou rely on their automatic table to do the calculation and adjustment of errors. Professional leagues/tournament do not do rounding and they have no need to since they are not converting the score to WP (See below).

Conversion of Final Score to WP

All the final score is then convert to WP by Final Score*50WP. Eg. 56.0*50 = 2800WP

As Players are “ranked” or compete in terms of the amount of WP they have, a player’s final WP count is based on their final score + shuugi. So depending on how much Shuugi you earned in the game, you can get around 4000WP! This makes fighting for Shuugi during the game extremely important.

Confusing? Yes. That’s why the practice session. 🙂

Details of how the coming session is conducted will be out in the next post.

Feng