Pon and Chi (2)
Which Pair Is Better to Save for Pon?
When you have multiple pairs that could potentially be used for pon,
it is usually better to keep the pair that is easier to pon.
Honor tiles are the easiest to pon,
and terminal tiles with low utility are also easier to expect from the table.
Example 1
Draw 
In Example 1, if there is no meaningful difference in how many copies are already visible,
the correct discard is .
The terminal tile ,
and the awkward blocked by the wall,
are both tiles you would rather expect to pon from the table.
If you compare and ,
the more edge-side tile is also a little easier to pon.
Think About How You Expose a Chi
Some hands can chi the same discard in more than one way.
Here are several cases where the exact way you call makes a difference.
Example 2
Discarded Dora
Suppose in Example 2 your upper player discards and you are going to call.
Here, you should take it as a kanchan chi.
Ryanmen chi
Chi 
Kanchan chi
Chi
If you chi it the first way, the hand is locked into a guaranteed 2000 points.
But with the second shape, drawing the dora makes 3900,
and drawing 
also creates the possibility of 456 sanshoku.
Example 3
Pon 
Dora
Sometimes the way you call even changes the final wait.
For Example 3, when is discarded,
you might be tempted to choose between taking 
to make a wait,
or taking to make a wait.
But in fact, both are wrong.
If you take it as a kanchan chi, the hand becomes a sanmenchan.
Chi Pon Dora
Example 4
Pon 
Especially in flush hands, it is common for a tile to be callable as a ryanmen chi and also as a kanchan or penchan chi.
Most of the time, the kanchan or penchan chi is better,
but sometimes the ryanmen chi is the correct choice.
In Example 4, if is discarded,
it is a big mistake to take it with as a kanchan chi.
Here, if you do not take it as a ryanmen chi, the 
wait disappears completely.
Correct shape
Chi 
Pon
Shapes like this may not come up all the time,
but whenever you chi, get into the habit of checking:
“Does the remaining shape change depending on how I take this chi?”
Original Japanese page: http://beginners.biz/naki/naki04.html