Patterns that should be back from ready hand even if it breaks the completed elements

 

Answer

Commentary

Patterns that should be back from  ready hand even if it breaks the completed elements

If you are an advanced player, you don't need an explanation, and most people will discard the 1m.

It is ready hand whether you discard 2m or 4s.

Moreover, drawing 1m,5m, 7m, 3p, 5p, 3s, and 5s gives this hand Flat hand.

And 4m, 8m, 2p, 6p, 2s, and 6s is good form to call Riichi.

Still, we should discard 1m  here.

The reason are that, 

①　Score

②　Whether or not you can call

If you discard 1m, you can back to ready hand by drawing 4m, 8m, 2s, 5s, 3s, 6s.

This can clear  the criteria (6 or more types) for baking from ready hand.

 And, you can call for Riichi by twice or Four times the score ( flat hand, and all simples).

If you draw 4m or 8m, you can get triple sequences.

Next merit is that whether or not you can call.

You don't need to draw 4m, 8m, 2s, 5s, 3s, 6s yourself.

If left side player discard it, you can call for chow for the same amount of points as if you had discarded 2m and 4s.

Acceptance of 6 or more types can back from ready hand.

In addition, if your hand is the above two conditions , you 'should'  back.