Basic Strategy 5: Hand Discussion – 1

Another basic strategy article translated from the JPML site. Original link is at the bottom of the article. We now begin a long discussion on the various yaku in riichi mahjong.
In Riichi Mahjong, we have ‘yaku’.
‘Yaku’ are particular hand shapes.
The units to count yaku are ‘han’.
In Japanese mahjong, you have to create four sets and have one pair as a head. If you don’t have a yaku, then you can’t go out on the hand.
This is called ‘i-han shibari’.
For the next several articles, I want to introduce the yaku.
For those who are just starting out in mahjong, you should first learn riichi and menzen tsumo (fully concealed hand).
Riichi 立直 リーチ Closed / 1 Han
Keywords: Self Ready
☆ Even if you don’t have a yaku, you can reach to go out.
With your initial deal and/or subsequent draws, you reach ready. You declare that you’re ready and if you go out, that is one han.
It does not matter what your hand looks like. If you have dora or additional yaku, this adds to that score.
After declaring riichi, you must discard any other drawn tiles unless it is your winning tile. (Unless you can declare a concealed hand that does NOT change the shape of your hand).
The procedure of declaring riichi is as follows:
- Declare riichi
- Discard a tile and turn it to the side
- Place a 1000 point stick on the table
If no one wins off your discarded tile that you riiched with.
(If someone does win off this tile, you do not need to pay the 1000 points.)
Pros
-If you riichi, you can go out on any hand.
-Riichi is a yaku so adds another han to your score.
-Other players will not want to play into your hand, and thus it will be harder for them to build their own hands.
-If ippatsu or ura dora rules are being played, you might get an even higher score.
Examples of when you should reach:
-You have no yaku but several dora.
-You have three or more possible winning tiles.
Cons
-You can’t change your hand after you have riiched.
-Because people know you’re ready, other players may play defensively making it harder to win.
-You can’t play defensively even if you draw a dangerous tile.
Examples of when you shouldn’t reach:
-You are ready, but you don’t have any dora.
-When another player is going for a full flush or yakuman.
Combines with: All yaku other than double riichi.
Tsumo自模 ツモ (Officially called Fully Concealed Hand or menzen tsumo) Closed / 1 Han
Keywords: Total Self Win
☆ You can win with a closed tsumo even if you have no other yaku.
☆ If you have called any tile (pon, chi, open kan), you cannot count this as a yaku.
With your initial deal and/or subsequent draws, you reach ready and draw your winning tile. This counts as a yaku. There are no restrictions on the shape of the hand.
Pros
– You’re ready, but it’s not a hand you should reach on or by changing your hand you can get a yaku. In these situations you can still win with a closed tsumo.
-If you reach and then tsumo, you have 2 Han in total to add to your score.
Cons
-There are no disadvantages of this yaku.
Combines with: All yaku except Toitoi (all pungs), Chankan (robbing the kong) and Houtei (bottom of the river)
