Calling Techniques (2)
This page introduces advanced techniques for open Tanyao.
Some people may dismiss them as small tricks.
But in today's red-five mahjong, these "small tricks" may be exactly where the real edge comes from.
Sanshoku used to be one of the glamorous showcase yaku, but now it has been pushed well into a supporting role.
What really rose to prominence after red tiles were introduced was Tanyao.
Open Tanyao overwhelms many other yaku in pure speed, and once red tiles are involved it has plenty of value as well.
It is fair to call it one of the strongest yaku in modern red-five mahjong.
Figure 1: East 1, Dealer, Turn 6
Dora
Even with a hand like this, you should already be thinking about open Tanyao.
If you insist on a closed riichi route, the acceptance is not actually that wide.
You still need the manzu and pinzu sides both to improve into ideal ryanmen shapes, which means you can easily fall behind the table.
So if the player on your left discards 
, , 
, 
, or 
, you should chi.
The pinzu and souzu parts are each already close to forming two melds of their own.
From there, you are only trying to connect them into a straight line.
Even if the theoretical tile count does not look dramatically larger, the fact that you can use the player on your left's discards makes this open Tanyao route vastly faster than staying closed.
And if you draw one more red tile, mangan is easy.
The Changed Shape: Figure 2
Figure 2: 
Chi 
Chi 
From Figure 1, there is no need to spend your imagination trying to see Sanshoku shapes like 234 or 456.
This idea of a "highest possible form" is often just a fantasy.
Instead of dreaming about a pretty Tanyao Sanshoku that may never become real, what matters is this:
picture the realistic open Tanyao shape that can actually win the fastest.
Figure 3: East 1, North Seat, Turn 5
Draw Dora
Just because you have three dora, does that mean you should riichi immediately?
Of course not.
Silent tenpai is even less worth considering.
In both ease of winning and expected value, cutting and shifting to the faster route looks better.
That is because you can then call on , , , 
, 
, , and 
to form good-shape tenpai.
If you stay menzen, then yes, tiles like , , and also become draws that help.
But even if you have to break the current tenpai to take the faster route, the gain in actual completion rate more than pays for it.
Figure 4: East 1, West Seat, Turn 9
Dora
Suppose the player on your left discards 
.
Many players think, "ah, two copies are already visible," and pass on it while reaching for the wall.
That is a soft play.
Here you should chi the kanchan and convert the hand to Tanyao.
If you insist on keeping it closed, the hand will most likely end up waiting around the dora indicator and become very hard to win.
And right next to dora is almost never going to come out even if you riichi.
As a tsumo target, there are only two known copies left, so the expectation is low.
If the closed route is visibly hard to win, there is no reason to stay attached to it.
Figure 5: East 1, Dealer, Turn 8
Dora
You may think, "surely not this hand too?"
But yes, even here you should consider open Tanyao.
If it were me, I would chi-switch on ; if the rules forbid kuikae, then I would cut .
And if the player on your left discards , I would call it and cut .
This is a hand that will be painful to advance even if you keep it closed.
At this turn, with this shape, it is already very difficult to expect a clean riichi win.
Rather than that, you should look for your way out through a Tanyao hand that can use pon and chi.
When you have dora or red tiles and really want to win,
or when you are dealer and absolutely want to keep the dealership,
open Tanyao is a very effective weapon.
Even now, many players still instinctively dislike calling mahjong.
But comments like "it is ugly" or "it is cheap" do not deserve any attention.
The stronger player is the one who can decisively turn a hand like this into open Tanyao.
Original Japanese page: http://beginners.biz/naki/naki14.html