Wanna some WWYD?

[Yukun]

Are you hungry for \"What would you discard?\" topics?

Here is some quiz I picked up.
There quiz have a good explanation, so I hope every one can enjoy and learn from these quiz!

1)

your 9th draw

dora:

you have 26000 South round-1 You are the dealer.


2)

your 9th draw

dora:

the situation is same as one above.


I will post the answers a few days later.

[Poochy]

1. - I think that yields the most possibilities for a Pinfu + Tanyao

2. - Depending on what comes soon after, I may try to turn this into a Toitoihou or Chiitoitsu, but regardless, I think 4566 makes the best fallback plan.

[Shirluban]

1)

2) 6 different tiles (17 live tiles) made me tenpai.

[5dots]

1) . will be very useful and makes you ready when you get dora ( or red-dot)

2) . A pair of for the \"eye\" is enough and I will try to make this hand ready as fast as I can (of course getting 1 more is the best)

[Yukun]

Well not so many people have answered, but I\'m posting the answers.

1)A:

Reason: discarding any manzu is not a good idea since, only draws of pinzu will lead you to tenpai.

is not good enough since, you are losing possibility of tanyao-pinfu-dora2

is best because tsumo / lead you to good 3men-tempai. Also tsumo / will lead you to also good tempai such as: ---> waiting for

--->waiting for


2)A:

It is close to 7-pair-hand, but you should aim for shuntzu (straight tiles).
This is because you need to think that you cannot pon easily;therefore, is not the best discarding.

is best because it can follow your hand in case you pon or draw , also when you draw 1~4dots and 4~8bams plus reddragon, they will lead you to a good shape of tempai.(at least better numbers of waiting tiles than Chiitoitsu)

And do not forget! you are the dealer and it is the last chance to be a dealer, so try to finish up your hand as quickly, wide as possible!

Well done 5dots!!

[zzo38]

1) 8pin
2) 6pin, I can throw the other 6pin on next turn

[or2az]

Came across this really early WWYD in the Reach Mahjong section from 5 years ago. They are making my brain hurt so I thought I would re-post them in a more visual format and perhaps see if anyone has any additional comments or opinions (and maybe some help with the reasoning). No previous discard info was given.
The 1st is as follows:

It is South #1, 9th turn, you are dealer with 26000, and 3dot is the dora.
WWYD?

Here is the 2nd one:

Same situation as above except dora is the red dragon.
WWYD?

[Ignatius]

Came across this really early WWYD in the Reach Mahjong section from 5 years ago. They are making my brain hurt so I thought I would re-post them in a more visual format and perhaps see if anyone has any additional comments or opinions (and maybe some help with the reasoning). No previous discard info was given.
The 1st is as follows:

It is South #1, 9th turn, you are dealer with 26000, and 3dot is the dora.
WWYD?

Here is the 2nd one:

Same situation as above except dora is the red dragon.
WWYD?

In the first I would choose to throw . And probably next will follow it depending on tsumoed tiles, of course. I see there enough potential for Tanyao Pinfu.
For the second I´ll choose . Allowing to keep options for Chiitoitsu, or Toitoi. If things go really bad I would try with just Chun (red dragon) trio only. But only if I can call it.

If an opportunity to call comes, I´ll go for it, being on 9th turn, maybe is an option. Chances to improve the hand becomes low as you enter on the center of mid-game sometimes. So, why not just barrel forward attacking? Moreso having two dora that could be three if we´re lucky...

And if I don´t see chances, even Menzen Tsumo or or Menzen Tsumo Riichi, or Riichi only goes for me, if a bad situation comes, of course.

[Shirluban]

Came across this really early WWYD in the Reach Mahjong section from 5 years ago. They are making my brain hurt so I thought I would re-post them in a more visual format

Fixed.
We you see an old post with broken smiley/tiles, you can just PM me. It's easy for me to fix it.

[or2az]

Ignatius, I agree with both your choices.


Same situation as above except dora is the red dragon.

In this one, the original "answer" suggests tossing the and not the but I just can't go along with that.
Once you toss the 6, you are totally relying on getting the 5, or else the leftover 6, which is now not connected, must also be tossed.
As you stated, tossing the 7 keeps a few options open, like seven pairs and toi-toi, and you know if another red dragon becomes available, you will grab it for the 3rd dora . I see shirluban (and poochy) also chose the 7 five years ago, perhaps for different reasons.

[Iapetus]

1. 8-pin . The only total backfire is another 8p, and the 5m sort of backfires (5 tile wait tenpai instead of 9). Discarding 7m makes 58m total backfires, and discarding 4p makes 369p total backfires where 3p is the dora. 4m is plain worse than 7m, since it kills 45666-based shanpon waits. 6m makes the 4p near useless.


2. If discarding souzu, the discard should be 4s so you form a suji trap on the 7s, right? In any case,

6p discard has 14 tiles to tenpai, then 7 tiles to win in tenpai. (The plan is to get rid of the 6p pair completely and focus on the 14p and 58s ryanmens. The next discard is the second 6p in pretty much any case except 5p, where the 3p goes).

4s discard has 20 tiles to tenpai, 4 of which lead to a 7 tile tenpai, 7 to a 4 tile tenpai and 9 to a 3 tile tenpai. (The plan is to win by a 14p / 6pC combo, or by chiitoitsu. Toitoi isn't an option, the hand has 2 shuntsu and triplets only improve those shuntsu shapes.)

Let's say that the time it takes to complete a wait with width X is 1/X. (In reality 1 would be some constant one can calculate, but it's irrelevant now). The time to complete two waits with widths X and Y is 1/X + 1/Y.

For 6p discard the time taken is 1/14 + 1/7 = 3/14 =~ 0.214

For 4s discard the width in tenpai differs. However, we can calculate the expected value of the width. That is of course SUM(P(tenpai)W(tenpai)). P(tenpai) is W(to tenpai)/W(to all tenpais). So the formula for time is

1/20 + 1/EV(tenpai) =
1/20 + 1/((4/20)*7 + (7/20)*4 + (9/20)*3) =
1/20 + 20/(4*7+7*4+9*3) =
1/20 + 20/(28+28+27) =
1/20 + 20/83 =~ 0.291

So, we see that while 4s discard may be faster for tenpai, it's slower to win because it will likely end up with a worse wait. Discarding 6p, the hand will complete in 75% of the time it will complete in if you discard 4s.

Other factors:

4s has a scoring advantage. 7 pairs is 6400 points, more than the 5200 of riichi. Riichi with the shanpon wait into a chun tsumo is haneman.

4s has the advantage of damaten with chiitoitsu, improving its speed (over what I calculated).

6p has the advantage of better flexibility. Even if it backfires by drawing 7s or getting the chun, it only transforms into an excellent iishanten shape. Drawing 235p36s also creates a similar excellent shape. The only way discarding 6p truly backfires is if you draw another 6p. In other cases it's exchanging a bad wait tenpai for a great shape iishanten, or good wait tenpai for amazing shape iishanten.


So, based on the better raw speed and the flexibility advantage, I discard 6p.

[or2az]

The plan is to get rid of the 6p pair completely and focus on the 14p and 58s ryanmens

I can see how this would work. You discard a 6p, try to complete one of the ryanmen and discard the other 6p, and rely on the other ryanmen for the win.
Question: Do you riichi, and if you don't, and happen to draw a 3rd red dragon (dora), do you keep it and reduce your wait, or discard it?

4s has a scoring advantage. 7 pairs is 6400 points, more than the 5200 of riichi. Riichi with the shanpon wait into a chun tsumo is haneman.
4s has the advantage of damaten with chiitoitsu, improving its speed

I can also see how going this route would be a decent alternative.

I am a little baffled as to why the 4s would be a better discard than the 7s. Can you elaborate a little more?
To me, it seems that 4566 would be better than 5667 in this situation?
I did a little reading on the suji trap, which you mentioned above. I guess it didn't help.

[Iapetus]

The plan is to get rid of the 6p pair completely and focus on the 14p and 58s ryanmens

I can see how this would work. You discard a 6p, try to complete one of the ryanmen and discard the other 6p, and rely on the other ryanmen for the win.
Question: Do you riichi, and if you don't, and happen to draw a 3rd red dragon (dora), do you keep it and reduce your wait, or discard it?

You have no yaku, so you have to riichi. It's riichi dora 2, 5200 ron or mangan tsumo.

If you draw the chun before tenpai, you keep it. It doesn't reduce your wait, it makes it much better.


lead to tenpai.


lead to tenpai!

If you draw the chun, then 14p58s, you do have a choice between discarding the chun for a 7 tile wait or discarding one of 2p47s for a 6 tile wait. In that case, the two han the 3rd chun gives are more than worth having a slightly narrower wait.

If you draw a chun in tenpai, you're already in riichi, so you can't add it. Discarding it isn't bad since you already have 2; the only thing that can hurt you is someone having a dora tanki tenpai. That's not that likely.

If for some reason you were damaten and drew a chun, you would keep the chun and reduce your wait from 7 tiles to 6 tiles.

[or2az]

You have no yaku, so you have to riichi. It's riichi dora 2, 5200 ron or mangan tsumo.


lead to tenpai.

But suppose you drew the 4p

Now you have a yaku. Do you still riichi? (from what you have said, I would think the answer is still yes)

Last question;
In the unlikely chance that a 3rd red dragon is discarded pre-tenpai, would you open the hand and claim it?
(extra dora, extra yaku, no riichi, no chance of iipeiko, possible faster win)

[Iapetus]

Yes, 3 han good wait is a riichi in the typical situation.

It is fine to pon the chun, as doing so both increases the minimum score and the path to tenpai. There's a possibility of calling to tenpai as well.