Why isn't Tsumo Pinfu ever set as 2 Fan 30 Fu?!

[Zi Rong Low]

I think most of you are aware of the option of making a fully concealed hand with Pinfu as either 2 Fan 20 Fu, or forfeit the \"Pinfu\" and make it 1 Fan 30 Fu. I understand that 2 Fan 20 Fu is technically the same value as 1 Fan 40 Fu.

But why not just leave it as it is and make it 2 Fan 30 Fu (20 base + 2 for tsumo = 22 --> 30 Fu) ?

I can understand Chiitoitsu being given 1 Fan 50 Fu/ 2 Fan 25 Fu because it\'s a different hand structure, and for a revealed Ron hand with no Fu-worthy melds/pair/waiting status to be 20 Fu.

However I feel that to devalue a common hand like this is kinda stingy, 30 Fu is already very common and low enough as it is, let alone removing a Fan from it...

Thanks in advance.

[essnov]

I guess whoever made the decision about that rule was sticking to the idea that pinfu = no points.

Here\'s my take on it:

I remember reading somewhere else on this forum that tsumo was one of the most common yakus. Some members of the forum were arguing about whether or not awarding 1 han for tsumo on a concealed hand was too much.

People argued that when a tsumo, something which is so common, pushes you from a mangan to a haneman, then that is just too much of a reward.

Others said that the most tsumo was going to give you was a 1.5x bonus -- ie, adding tsumo to a 5 han hand.
For smaller hands the bonus is somewhere around 1.33.

What I\'m saying is that maybe, in addition to keeping with the \"no points\" idea for pinfu, that small disadvantage helps keep menzen tsumo balanced.

I realise I\'m focusing on tsumo rather than pinfu, but I think that pinfu is so common that this is still relevant.

However, I don\'t think that this small fu penalty in the occasional case of tsumos is any great detriment to the value of pinfu itself: it is very easily & rapidly achieved and is readily combined with other yakus.

In conclusion, I think that keeping a pinfu tsumo at 20 fu serves nicely to keep menzen tsumo hand value bonuses reasonably sized, while having little effect on the attractiveness of pinfu as a yaku.

A few numbers for quick perusal by general public:

(assuming 1 of the yakus in all of these hands is pinfu)

Han - Ron PO - Tsumo PO - relative PO increase w/ tsumo
1 ----- 1000 ----- 1300 ------------ 30%
2 ----- 2000 ----- 2600 ------------ 30%
3 ----- 3900 ----- 5200 ------------ 33%
4 ----- 7700 ----- 8000 ------------ 4%
5 ----- 8000 ----- 12000 ----------- 50%

In comparison, if we said tsumo on a pinfu starts at 30 fu, then the relative PO increase would be 100% until the han count reaches 4, and then fall to 50% again at 5. A tsumo on a simple tanyao, pinfu, dora 1, would pay 7700... which, in my opinion, is a tad too much!

edit: Just found a poll which is relevant to this post on mahjongnews.com. 60% (or 20/33) of voters think the reward for self draw is too much, and 40% (or 13/33) think it is just okay. The population is small, though, so I can\'t say if this means anything.

[Shirluban]

I guess whoever made the decision about that rule was sticking to the idea that pinfu = no points.

It\'s exatly that: pinfu is a no points hand, and not an all chow hand like many people believe.

Just found a poll which is relevant to this post on mahjongnews.com.

I suppose you are talking about the pool labeled "The reward for Self-Draw \'Hu\' in MCR is… ".
This pool is about MCR (aka Chinese Official), not Riichi.
These two rules have a very different way to reward a self-draw. So much we can\'t use this pool to get conclusions about Riichi.

[essnov]

Just found a poll which is relevant to this post on mahjongnews.com.

I suppose you are talking about the pool labeled "The reward for Self-Draw \'Hu\' in MCR is… ".
This pool is about MCR (aka Chinese Official), not Riichi.
These two rules have a very different way to reward a self-draw. So much we can\'t use this pool to get conclusions about Riichi.

Hahaha-- right. My eyes just passed over MCR somehow and I assumed it was talking about riichi. ^^;

[Zi Rong Low]

I guess whoever made the decision about that rule was sticking to the idea that pinfu = no points.

It\'s exatly that: pinfu is a no points hand, and not an all chow hand like many people believe.


Ahhhh, yeah that explains it. I was thinking of Pinfu as all chows coz the shape was more apparent. Thanks for the explanation! :)