Chapter 3
Riichi mahjong basics
3.1 Learning strategies
Mahjong is a game of skill and luck. There is a set of strategy
principles you can learn to improve your skills, but acquiring skills is
neither necessary nor sufficient to win a game. On the contrary, with
luck, an unskilled player can easily defeat strong players in mahjong.
At least in the short run, game outcomes are governed more by luck
than by skills.1 However, learning strategy principles is crucial to
improve your performance in the long run. Moreover, you will be
able to enjoy the game in greater depth once you understand these
principles.
Because of the probabilistic nature of the game, making the best
choice does not always lead to the best outcome. The best choices
are those that lead to the best outcome, on average. An evaluation of
our choices thus requires a probabilistic (i.e., statistical) assessment of
different options. For example, consider the following hand.
a $$L
What would you discard?
This hand becomes ready to win if you discard or . Letās com-
pare the two choices.
1 An interesting question would be: how short is the āshortā run here. That is,
how many games do we need in order to discern a strong player from weak
players? Studies show that we would need at least 100 games or so to have a
reliable estimate of our skill levels. Given that EMA tournaments usually have
only 8 games, winning at these tournaments requires quite a bit of luck.
3.1. LEARNING STRATEGIES 49
ā¢ Discard ) you wait for (2 kindsā8 tiles)
ā¢ Discard ) you wait for (2 kindsā4 tiles)
Which discard choice is better? Although both of the two choices
yield a 2-way wait, waiting for is much better than waiting
for , probabilistically speaking. With the wait, there are
four tiles of and another four tiles of to win on, leaving at most
eight winning tiles.2 With the wait, on the other hand, you
have already used up two tiles of and two tiles of yourself,
leaving at most four winning tiles. It is clearly better to choose the
wait over the wait, because that will give you a higher
probability of winning this hand.
It is possible that, after you decided on the wait, your op-
ponents end up not discarding or at all, while discarding lots of
. This is the kind of thing that will happen often in mahjong (or
in any game of luck, for that matter). When things like this happen,
do not think that you made a bad call; you didnāt. You made the right
choice, but you were just unlucky. When we experience this kind of
bad luck, we just need to keep calm and carry on.
Before discussing a practical method of maximizing tile efficiency
in the next chapter, I will discuss some basic principles of tile effi-
ciency in this chapter. In doing so, I introduce several key terms we
use in later chapters. I will also provide the original Japanese term
for each (shown in this font). I do so because you may find these
Japanese terms used in some online strategy discussions in English.
2 Of course, the number of winning tiles could be smaller than eight if some of
them have already been discarded.
50 CHAPTER 3. RIICHI MAHJONG BASICS
3.2 Basic building blocks
3.2.1 Tiles
Mahjong tiles can be classified into two categories ā number tiles
and honor tiles.
Number tiles
Number tiles
Cracks (characters) Manzu Č·ff
Dots (circles) Pinzu
Bamboos Souzu a
We further classify number tiles into simples (tanyao hai; tiles be-
tween 2 and 8) and terminals (yaochu hai; 1 and 9). They are dif-
ferentiated because they serve different yaku and generate different
minipoints (fu).
It has become quite common to include some red five tiles. For
example, most games on Tenhou have one red five tile in each suit,
. These tiles are included in place of regular fives; we have
three regular fives and one red five in each suit. Red fives are treated
as dora regardless of the dora indicator. When a 4 in a given suit is
the dora indicator, the red five in that suit will be a double dora tile.
3.2. BASIC BUILDING BLOCKS 51
Honor tiles
Honor tiles
Dragon tiles # $ %
White (haku) Green (hatsu) Red (chun)
Wind tiles ffl ! "
East (ton) South (nan) West (sha) North (pei)
Some honor tiles are value tiles (fanpai / yakuhai); we get one han
if we collect three identical value tiles. All dragon tiles are value tiles
regardless of the round and seating. On the other hand, the value
status of wind tiles depends on the round and the seating. East tiles
are value tiles for everyone during the East round, and South tiles are
value tiles for everyone during the South round. In addition, each
player gets their own seating wind as a value tile. For example, West
tiles are value tiles only for the West player, but they are valueless
wind tiles (otakaze) for other players.
52 CHAPTER 3. RIICHI MAHJONG BASICS
3.2.2 Group (mentsu)
One of the major goals in playing mahjong is to win a hand.3 To
win a standard hand, we need to complete four groups (mentsu) and
one head (atama; final pair).4 Groups can be classified into two kinds
ā run and set.5
ā¢ Run (shuntsu; chow / sequence) is a set of three consecutive
number tiles: e.g., ff, .
ā¢ Set (kotsu; pung / triplet) is a set of three identical tiles: e.g.,
, $$$.6
3.2.3 Ready and n-away
We say a hand is ready (tenpai) when the hand can be complete
with one more tile. For example, the following hand is ready.
Ready hand
a%%%
This hand becomes complete with either or . We say that this
hand waits for .
3 Another important goal is not to deal into an opponentās hand. See Chapter 8
for discussions of defense strategies. However, the most important goal of all
is to win a game. Winning a hand and playing defense are merely two means
to this end. See Chapter 10 for more discussions of this.
4 There are three exceptions to this; chiitoitsu (Seven Pairs), kokushi musou
(Thirteen Orphans), and nagashi mangan (All Terminals and Honors Discard)
do not require four groups and one head.
5 EMA rules refer to run as āchowā and set as āpung.ā I realize that my use of
different terminology here might be confusing at first, but I hope you will get
used to it soon.
6 Technically speaking, there is a third type of groups, namely quad (kantsu;
kong), a set of four identical tiles. We treat quads as a variant of sets. See
Section 9.3 for discussions on this.
3.2. BASIC BUILDING BLOCKS 53
We say a hand is 1-away from ready (1-shanten) when the hand
can become ready with one more tile. For example, the following
hand is 1-away from ready.
1-away hand
a%%%
This hand becomes ready if you draw any of . We say
this hand accepts (5 kindsā16 tiles) as any of them can
make this hand advance from 1-away to ready. Tile acceptance (ukeire)
refers to the kinds and the number of tiles a hand can accept. Other
things being equal, having a 1-away hand with greater tile acceptance
is better than having one with smaller tile acceptance.
More generally, we say a hand is n-away from ready (n-shanten)
when the hand can be ready with n more steps. For example, the
following hand is 2-away from ready.
2-away hand
aa%%%
This hand accepts all the tiles that the 1-away hand above accepts
(), plus seven additional kinds of tiles a.7
The hand will become 1-away if any of these tiles gets drawn.
A hand can also be 3-away, 4-away, 5-away, or 6-away from ready.8
In practice, however, there is not much point in distinguishing 3-
away hands from 4-away (or worse) hands. You thus need to be able
7 will make this hand 1-away for chiitoitsu (Seven Pairs).
8 6-away happens when a hand has no pair, in which case it takes 6 more tiles to
make it ready for chiitoitsu.
54 CHAPTER 3. RIICHI MAHJONG BASICS
to distinguish between four kinds of hands ā ready hands, 1-away
hands, 2-away hands, and 3-away or worse hands.
Tile acceptance shrinkage
As n gets smaller and the hand gets closer to completion, the
kinds and the number of tiles it can accept will necessarily get smaller.
Consider the three stages of a hand we have seen above.
ā¢ When 2-away, it accepts: a.
ā¢ When 1-away, it accepts: .
ā¢ When ready, it waits for: .
Tile acceptance is minimized when the hand is ready. Note also that
it is virtually minimized when it is 1-away. This is because with a
ready hand you can utilize not only the tiles you draw but also the
tiles discarded by others to complete the hand. With n-away hands,
however, you have to rely (almost) solely on the tiles you draw your-
self to advance your hand.9 Therefore, in choosing a discard from a
2-away hand, we should try not to make for a 1-away hand with too
small tile acceptance.
Advancing your hand
To win a hand, we need to advance our hand by reducing the n of
an n-away hand until it is ready. When a hand is 2-away, we should
aim to make the hand 1-away. When a hand is 1-away, we should aim
to make the hand ready. For example, consider the following hand.
9 Melding (calling pon / chii) is not always possible. For example, the 2-away
hand above can accept if you draw one, but you can neither pon nor chii .
3.2. BASIC BUILDING BLOCKS 55
2-away vs. 1-away
Č·ffff a $$$
What would you discard?
Discarding makes the hand 2-away, whereas discarding either ff
or makes the hand 1-away. You should thus discard ff or to
make the hand 1-away. Reverting a 1-away hand to 2-away makes
sense only in some exceptional cases where tile acceptance at 1-away
becomes unbearably small (i.e., fewer than 2 kinds). With this hand,
the hand will be able to accept (3 kindsā12 tiles) when it
becomes 1-away.
CAN YOU GUYS NOT READ?!
I KNOW EEVEE SUCKS ASS.
I KNOW ABSOL SUCKS ASS.
I KNOW USING THEM PUTS ME AT A HUGE DISADVANTAGE FOR NO REASON WHATSOEVER.
I KNOW REFUSING TO USE RESTRICTED LEGENDARIES PUTS ME AT A HUGE DISADVANTAGE FOR NO REASON WHATSOEVER.
WHEN I MAKE POSTS THAT CLEARLY STATE:
I WILL NOT BE CHANGING THE SPECIES.
AND
I MIGHT CHANGE DRAGAPULT. AND ONLY DRAGAPULT.
THAT DOES NOT MEAN I AM NOT WILLING TO TAKE ADVICE AND CRITICISM, JUST BECAUSE I GET PISSED AT PEOPLE WHO INSIST ON THINGS THAT THEY KNOW I KNOW.
I KNOW MY TEAM SUCKS ASS. I NEED TO KNOW WHAT TO EQUIP THEM WITH TO MAKE THEM SUCK THE LEAST AMOUNT OF ASS.
SAY IT WITH ME NOW:
NATURES
EVS
IVS
MOVES
ABILITIES
HELD ITEMS
OR EVEN JUST THE ROLES THEY SHOULD PLAY
OR STRATEGIES ON HOW TO USE THEM
I WILL ACCEPT ADVICE ON LITERALLY ANYTHING EXCEPT THE SPECIES OF MY TEAM MEMBERS.
ITāS NOT HARD TO WRAP YOUR HEAD AROUND.
1 Like
76 CHAPTER 3. RIICHI MAHJONG BASICS
3.4 Waits
There are ļ¬ve basic wait patterns, as summarized in Table 3.5.
More complicated wait patterns can emerge when some of these ļ¬ve
basic patterns are combined.
Table 3.5: Five basic waits
Name Japanese Example Wait Acceptance
side wait ryanmen - 2 kindsā8 tiles
dual pon wait shanpon 2 kindsā4 tiles
closed wait kanchan a 1 kindā4 tiles
edge wait penchan 1 kindā4 tiles
single wait tanki 1 kindā3 tiles
As we can see in the table, side wait is the strongest of all the basic
waits in terms of the kinds and the number of tiles to win on. Single
wait appears to be much worse than others, but single-wait hands
tend to have many possibilities of improving the wait and/or scores
further. Moreover, single wait of an honor tile has a relatively high
chance of winning it by ron.
Stretched single wait and semi side wait
Table 3.6 summarizes two wait patterns, each of which can be
thought of as a combination of some basic wait patterns. As I men-
tioned before, a stretched single shape in a ready hand forms a 2-way
single wait. It is a decent wait pattern, as the number of tiles to win
on (2 kindsā6 tiles) is twice as big compared with a regular single
wait.
3.4. WAITS 77
Table 3.6: Stretched single wait and semi side wait
Name Example Waits Acceptance
stretched single wait 2 kindsā6 tiles
semi side wait - 2 kindsā6 tiles
However, stretched single wait should not be confused with side
wait for a few reasons. First, the number of tiles a 2-way stretched-
single-wait hand can win on is at most 6, whereas it is 8 for a 2-way
side-wait hand. The diļ¬erence between 6 and 8 is non-trivial. Sec-
ond, stretched single wait is still a variant of single wait, which means
two things. On the one hand, we cannot claim pinfu when the wait is
stretched-single wait. For example, the following hand has no yaku
and hence we cannot win it by ron without calling riichi.
Č·
On the other hand, we get 2 minipoints (fu) with a stretched single
wait. For example, if we win the following hand by drawing , we
get 40 minipoints (20 base minipoints + 8 for a concealed set of honor
tiles + 2 for self-draw + 2 for single wait = 32, rounded up to 40).15
Č· %%%
When we have a side-wait protorun right next to a pair (e.g., 1123,
2234, 7899, etc.), we call it semi side wait. We distinguish this from
regular side wait for two reasons. First, the number of tiles to win
on is smaller (6 rather than 8) because we are already using 2 of the
15 We will discuss methods of scoring and minipoints calculations extensively in
Chapter 6.
78 CHAPTER 3. RIICHI MAHJONG BASICS
8 winning tiles in our hand. Second, we can treat this wait pattern
either as single wait or as side wait, depending on which interpre-
tation gives us a greater score. For example, consider the following
hand.
Č·
We will treat the wait in this hand as side wait because that will give
us pinfu. However, consider the following hand that has the exact
same wait pattern: .
Č· %%%
If we win this hand by drawing , we will treat the wait as single
wait: + , which will give us 40 minipoints. If we treated
the wait as side wait: + , we would get only 30 minipoints.
Of course, if we win this hand on , we cannot think of the wait as
single wait (because it is not). Similarly, if we win it by ron, it does
not make a diļ¬erence if it is side wait or single wait (either way we
get 40 minipoints).
3.4. WAITS 79
3-way side wait
When a side-wait protorun is combined with an adjacent run, we
get a regular 3-way side-wait pattern. There are only three of this
kind, summarized in Table 3.7.
Table 3.7: Regular 3-way side wait
Example Wait Acceptance
Č· --ļ¬ 3 kindsā11 tiles
-- 3 kindsā11 tiles
a -- 3 kindsā11 tiles
When we have a stretched single shape or semi side-wait shape
combined with an adjacent run, we also get a 3-way wait pattern.
Table 3.8 summarizes some examples.
Table 3.8: Some irregular 3-way waits
Example Wait Acceptance
Č·ļ¬ ļ¬ 3 kindsā9 tiles
- 3 kindsā9 tiles
a -- 3 kindsā9 tiles
Notice that the number of tiles to win on in each pattern is smaller
than those for the regular 3-way side waits, although the kinds of tiles
to win on are the same (either 1-4-7, 2-5-8, or 3-6-9). This is because
we are already using some of the winning tiles within the hand.
80 CHAPTER 3. RIICHI MAHJONG BASICS
Notice also that not all the wait patterns qualify as side wait, so
claiming pinfu is not always possible (similarly, claiming single wait
is not always possible). For example, the ļ¬rst pattern in Table 3.8 is
essentially a 3-way stretched single shape; none of the waits embed-
ded in this shape qualiļ¬es as side wait. In the second pattern, if we
win on , the wait must be interpreted as single wait; if we win on
, the wait must be interpreted as side wait; and if we win on ,
we adopt whichever interpretation that generates the higher score.
In the third pattern, winning on allows us to claim single wait if
doing so gives us a higher score.
Complex waits
When a set is combined with a ļ¬oating tile nearby, we get some
complex wait patterns with multiple waits. Table 3.9 summarizes a
few examples of irregular waits that involve a set and a ļ¬oating tile.
Table 3.9: Some irregular waits (set and a ļ¬oating tile)
Example Combination Wait Acceptance
single and edge 2 kindsā7 tiles
single and closed 2 kindsā7 tiles
single and side - 3 kindsā11 tiles
When a set is combined with a protorun, pair, or a four-tile shape,
we get even more complicated waits. Table 3.10 summarizes only a
few representative examples.
3.4. WAITS 81
Table 3.10: Some irregular waits (set and a protorun, pair, or a four-tile shape)
Example Wait Acceptance
3 kindsā5 tiles
3 kindsā5 tiles
"" " 3 kindsā6 tiles
Č·ļ¬ - 3 kindsā7 tiles
- 3 kindsā9 tiles
- 3 kindsā9 tiles
Č·ļ¬ 3 kindsā10 tiles
3 kindsā11 tiles
82 CHAPTER 3. RIICHI MAHJONG BASICS
3.5 Glossary
Simple tiles (tanyao hai) are tiles between 2 and 8.
Terminal tiles (yaochu hai) are 1 and 9.
Honor tiles (jihai) are non-number tiles (dragon tiles and wind
tiles).
Value tiles (fanpai / yakuhai) include dragon tiles, seat wind tiles,
and prevailing wind tiles. We get one han for a set of value tiles.
Valueless wind tiles (otakaze hai) are wind tiles that are neither
a prevailing wind tile nor a seat wind tile.
Run (chow / sequence; shuntsu) is a set of three consecutive num-
ber tiles.
Set (pung / triplet; kotsu) is a set of three identical tiles.
Quad (kong; kantsu) is a set of four identical tiles.
Protorun (taatsu) is a set of two tiles in the same suit that can be-
come a run when one more tile is added.
Pair (toitsu) is a set of two identical tiles.
Ready (tenpai) is when a hand is ready to win.
1-away (1-shanten) is when a hand can be ready with one more tile.
Perfect 1-away is when a 1-away hand has two side-wait protoruns
and two pairs.
Tile acceptance (ukeire) refers to the kinds and the number of tiles
a hand can accept.
3.5. GLOSSARY 83
Stretched single (nobetan) shape is a set of four consecutive num-
ber tiles.
Bulging ļ¬oat (nakabukure) shape is a four-tile shape that is made
up with a run and one ļ¬oating tile in the middle of the run.
Skipping shape is a four-tile shape made up with a run and one
ļ¬oating tile located at two tiles away from the run.
donāt ask too much about the context of this one you want to know as little about this guy as possible
Chapter 4
The five-block method
In introducing basic building blocks of riichi mahjong in the pre-
vious chapter, I have also touched upon a number of important tile
efficiency principles ā e.g., superiority of side-wait protoruns, the
value of having two pairs in a hand rather than three, and the value
of stretched single or bulging float shapes, to name a few.
These principles are all important, but trying to take all of the
important principles into consideration at once could be a daunting
task. We have to make our discard choice in a limited amount of
time,1 and tile efficiency is not the only factor we need to consider in
making a discard choice. Moreover, some of the tile efficiency prin-
ciples can at times clash with one another, requiring us to make a
judgement call about which principle to follow. For example, we may
at times wonder whether to retain a bulging float shape or to retain
two pairs in a hand, when we have to discard one of the two.
The five-block method I introduce in this chapter will help us
prioritize between competing principles and find the most efficient
discard choice quickly.2 The core idea of the five-block method is
deceptively simple; we first identify five tile blocks in a hand ā four
groups + one head, or their candidates ā and try to complete each
block.
1 Recall that, on regular (slower) tables on Tenhou, each discard choice must be
made within 5 seconds. In offline games, we should make choices even faster
so as not to irritate your fellow players.
2 As I mentioned in the Preface, the exposition of this chapter is based on Makoto
Fukuchiās books. In particular, I am indebted to Makoto Fukuchi 2015 Haik-
ouritsu Nyumon Doriru 76, Yousensha. ISBN978-4-8003-0634-0.
4.1. FINDING A REDUNDANT TILE 85
4.1 Finding a redundant tile
We all understand that a standard hand must have five blocks of
tiles ā four groups and one head ā to win. The five-block method
encourages us to be always conscious about five tile blocks in a hand.
Consider the following hand. What would you discard and why?
ff %%%
To figure out which tile is the least useful in this hand, letās divide
the hand into tile blocks, as follows.
|{z} ff|{z} | {z } | {z } %%%| {z } (4.1)
Notice that, although we do not know which block is going to be the
head and which blocks are going to be four groups at the moment,
the hand already has five tile blocks. This means that there is no need
to increase or decrease the number of blocks from here.
Looking at each of the five blocks, the pair of , the protorun
ff, and the set of % are all self-sufficient; we keep them as they
are. Our discard choice should thus be from the third or the fourth
blocks, or . Letās now compare these two closed-
wait blocks. While is being useful within the block it belongs to,
enabling the hand to accept , is completely redundant; the hand
can accept without having . Therefore, the ideal discard here is
.
There are two key points to remember in applying the five-block
method. First, we should not make any one of the five blocks ātoo
86 CHAPTER 4. THE FIVE-BLOCK METHOD
weak.ā3 In the current example, if we discard , the block
becomes an isolated closed-wait protorun, which is too weak com-
pared with the other blocks. Likewise, if we discard , this block
becomes a pair of . Since this hand already has two other pairs,
having a third pair makes all the pairs in the hand too weak.
Second, each of the five tile blocks should ideally have three tiles.
In the current example, the block has exactly three tiles and
so we should not choose a discard from this block. On the other hand,
the block currently has four tiles so we should discard one
from this block to make this a three-tile block.
Five-block method
Identify five tile blocks in a hand. Try to make sure:
(1) there is no block that is too weak; and
(2) each block has at most three tiles.
3 Basically, any block that is weaker than a side-wait protorun is a weak block.
4.1. FINDING A REDUNDANT TILE 87
Letās see another example.
ff## #Dora
We can easily see that there is one block in manzu (cracks), two blocks
in pinzu (dots), and a pair of white dragons, giving us four blocks.
This means that we need to have only one more block in souzu (bam-
boos). Therefore, we divide the hand as follows.
ff| {z } | {z } |{z} | {z } ##|{z} (4.2)
Since we should not create a block that is too weak, discarding or
ff is not an option. Notice that the block in souzu (bamboos) has
four tiles. We should thus discard one from this block. In case the
pair of white dragon later becomes a set, we should keep the pair
of , leaving or as a discard candidate. Given that has a
higher chance of creating a side-wait protorun, we should discard
. Then, none of the five blocks is too weak, and each block has at
most three tiles.
In the two examples we saw above, you might have been able
to identify the redundant tiles without really thinking too hard. If
so, that was probably because you have implicitly and unconsciously
applied the five-block method in your mind. The goal of this chapter
is to train our mind further, so that it becomes our second nature to
identify five tile blocks in a hand.
4.2. ALTERNATIVE CONFIGURATIONS 89
+ (recall the discussion of double closed shape in
Section 3.3.1). Therefore, this block can accept as well as -
to make two runs in pinzu. The block in pinzu will have six tiles, but
this is OK because this block is worth two.
To master the ļ¬ve-block method, we need to be able to instanta-
neously envision the ļ¬rst block conļ¬guration (4.3) the moment we
see this hand. However, that is not enough. We should also be able
to imagine an alternative conļ¬guration (4.4) at the same time. In the
game of mahjong, situations change very quickly each time a new
tile gets drawn or a new tile gets discarded. Therefore, the ideal
ļ¬ve-block conļ¬guration would also change accordingly as situations
evolve. We thus need to develop our skills to picture many possi-
ble ļ¬ve-block conļ¬gurations and to prepare for possible situational
changes that would call for a change in the conļ¬guration.
I provide several exercises in the following pages. The answer
key to each exercise is provided on the next page. Try not to look at
the answers before you actually derive your own answer.
Exercises: ļ¬nding a redundant tile
Exercise 1
What would you discard?
How do you divide the hand into tile blocks?
Č·Č· aa Draw
90 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 1
|{z} Č·Č·|{z} | {z } aa| {z }
2
With the draw of , we now have a 3-way side-wait block in
souzu (bamboos). or a could be our back-up candidate for
the head, in case we draw another Č·. Since there is a potential
for sanshoku (Mixed Triple Chow) of 345, we discard .
Exercise 2
What would you discard?
How do you divide the hand into tile blocks?
ļ¬
Draw
4.2. ALTERNATIVE CONFIGURATIONS 91
Answer 2
ļ¬|{z} | {z } | {z } |{z} | {z }
Before we drew the third , the pinzu (dots) tiles were
- + , so the was simply a ļ¬oating tile. Now
that we have another , the ļ¬ve-block conļ¬guration changes ac-
cordingly. The ideal discard is , as this has become redundant.
Exercise 3
What would you discard?
How do you divide the hand into tile blocks?
Č·Č·ļ¬ a Draw
92 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 3
| {z } Č· Č·ļ¬| {z } |{z} |{z} a| {z }
There are two āside wait plus oneā shapes, and a,
that might later become the head or a run. At this point, how-
ever, we cannot determine which one will be which, so we should
keep them as they are. One of the two Č· has become an obvious
redundancy so we should discard one.
Exercise 4
What would you discard?
How do you divide the hand into tile blocks?
Č·" Draw
4.2. ALTERNATIVE CONFIGURATIONS 93
Answer 4
Č·| {z }
2
|{z} |{z} | {z } "
The " is obviously redundant, but is also useless. Without
, the hand can accept . Since honor tiles can be used as a
safety tile (see Chapter 8), we discard ļ¬rst.
Exercise 5
What would you discard?
How do you divide the hand into tile blocks?
ļ¬ļ¬ a
Draw Dora
94 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 5
|{z} ļ¬ļ¬| {z } | {z } |{z} a| {z }
This is a bit diļ¬cult, as there are so many closed-wait protoruns.
Recall that each tile block should have at most three tiles and that
pairs are most valuable when there are two of them in a hand.
The block in pinzu (dots) has four tiles, so we discard one from
this block. Since is dora, we discard , leaving the double
closed shape around dora: .
Exercise 6
What would you discard?
How do you divide the hand into tile blocks?
Draw
4.2. ALTERNATIVE CONFIGURATIONS 95
Answer 6
| {z } | {z }
2
| {z }
2
Finding the best discard by actually comparing tile acceptance
counts for each possible discard candidate is super tedious. The
ļ¬ve-block method simpliļ¬es the process quite a bit. Since we
have two blocks in pinzu (dots) and two blocks in souzu (bam-
boos), we only need one block in manzu (cracks), hence one is
redundant. If we discard , the hand can be made ready with
11 kindsā34 tiles. If we discard or , the hand can be
ready only with 6 kindsā19 tiles.
Exercise 7
What would you discard?
ļ¬ a Draw
96 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 7
|{z} ļ¬ | {z } | {z } a| {z }
2
Do not discard the just because it forms a closed wait or
because discarding it gets us tanyao (All Simples). Avoiding
closed wait too much and being hung up on tanyao are two
pathologies common among intermediate players.
The block in souzu (bamboos) is actually not too bad; this is a
stretched single plus one, which can become either two runs im-
mediately (if we draw ), one run plus one side-wait protorun
(if we draw any of ), or one run plus the head (if we draw
or a). Note also that we need both and , because this
part may become the head if we get two runs in souzu (bam-
boos); when we get the head in souzu (bamboos), we will treat
this part as a side-wait protorun. We thus discard ļ¬
4.3. SELECTING TILE BLOCKS 97
4.3 Selecting tile blocks
All the hands we have seen so far in this chapter already have
five tile blocks. In practice, however, this is not always the case. A
hand can sometimes have fewer or more tile blocks. Since we need
to have exactly five blocks to win a hand, we will need to bump up
tile blocks by using a floating tile when we have fewer of them or to
discard some blocks entirely when we have a plethora of them.
In selecting which tile blocks to keep and which ones to discard,
we focus on a combination of the following three criteria:
- tile efficiency;
- hand value;
- the safety of tiles to be discarded.
As we will see below, we can sometimes find a block to discard based
on all the three criteria. Consider the following hand. How do we
divide the hand into tile blocks, and what would you discard?
Red
a Draw
We can see that the hand currently has six tile blocks, as follows.
| {z } | {z } |{z} |{z} |{z} a|{z}
Since the first two tile blocks are already complete and the third block
is the head, our discard choice should be from the last three tile
blocks, , , or a.
98 CHAPTER 4. THE FIVE-BLOCK METHOD
From a perspective of tile efficiency, discarding the block
means that we lose the ability to accept both and . On the other
hand, if we discard the a block, we only lose the ability to accept
; because of the block, we can still accept . We should thus
choose between the two blocks in souzu (bamboos). Keeping the
is desirable from a perspective of hand value (it is a red five) as
well as safety (discarding a is much safer than discarding ,
generally speaking). Therefore, the three criteria collectively suggest
that we should discard a.
In practice, however, satisfying all three criteria may not be fea-
sible. A common tradeoff we face is between speed and hand value.
That is, maximizing tile efficiency to gain speed often entails giving
up possibilities of pursuing an expensive hand. Consider the follow-
ing hand.
ffff
Letās divide the hand into tile blocks. There are several ways to do
this. One way to do this is to split it into the following blocks.
| {z } ffff|{z} |{z} |{z} |{z} |{z}
If we simply maximize tile efficiency, we discard , as we already
have six tile blocks and we wonāt need any more floating tile.
However, as it stands, the hand has no yaku and it is likely to be
a very cheap riichi-only hand. Moreover, the hand has three pairs,
which is not ideal as we saw in the previous chapter. Therefore, we
4.3. SELECTING TILE BLOCKS 99
might want to split the hand into the following five blocks.
ffff| {z } |{z} |{z} |{z} |{z}
We count the floating as an independent block, hoping it to grow
into a run. We also treat the tiles in manzu (cracks) as a single block,
hoping to get at least one group or the head out of it. We thus discard
one now, then another in the next turn. Depending on what
tile gets drawn, our five-block configuration will be different.
For example, suppose we draw and then . We will then have
the following.
ffff| {z } |{z} |{z} | {z } |{z}
We will discard the as a first step toward reducing the number of
tiles in the manzu (cracks) block to three. We can now see that this
hand has a potential of getting sanshoku of 345 as well as pinfu and
tanyao.
On the other hand, if we draw Č· and then , we can expect to
have two groups in manzu (cracks) so we will discard .
Č·ffff| {z }
2
|{z} |{z} |{z}
In selecting tile blocks, we should try to achieve the best balance
between speed and hand value. Donāt fantasize too much about get-
ting an expensive hand. At the same time, donāt fixate too much
100 CHAPTER 4. THE FIVE-BLOCK METHOD
about tile efficiency at the cost of hand value. This is, of course, easier
said than done; it is quite difficult even for advanced players.
Exercises: selecting tile blocks
Exercise 8
What would you discard?
How do you divide the hand into tile blocks?
ff Draw
4.3. SELECTING TILE BLOCKS 101
Answer 8
| {z } ff|{z} |{z} |{z} |{z} | {z }
The hand currently has six blocks so we need to get rid of one.
The block is the weakest ā it is the only closed-wait pro-
torun ā so we should get rid of this one. We should discard
first; if we draw we will discard to leave the possibility of
pinfu. If not, we discard next, and then .
Exercise 9
What would you discard?
How do you divide the hand into tile blocks?
a##
Draw
102 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 9
| {z } | {z }
2
|{z} a|{z} ##|{z}
We were planning to discard the block because this was the
weakest block among the six blocks in this hand. However, now
that we drew another , the block is now the weakest. We
thus discard .
Exercise 10
What would you discard?
How do you divide the hand into tile blocks?
Č·ff a"" Draw
4.3. SELECTING TILE BLOCKS 103
Answer 10
|{z} Č·ff| {z } |{z} | {z } a|{z} āā|{z}
The hand currently has six blocks so we need to get rid of one.
Comparing the two closed-wait blocks and , the
block is more valuable because it is adjacent to a run. If we draw
, we will get a 3-way side-wait block. On the other hand, the
block will only become a 2-way side-wait block when we
draw . We should discard first, not , because if we draw
next, we will discard the block.
Exercise 11
What would you discard?
How do you divide the hand into tile blocks?
ff a
Draw
104 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 11
ff|{z} | {z } |{z} |{z} a| {z }
2
Now that we have a 3-way side-wait block in souzu (bamboos),
we should get rid of one block. Comparing a closed-wait block
ff and two pairs and , we should value the closed-
wait block. This is because the hand has three pairs already so we
should get rid of one of them. Since we see a (remote) possibility
of sanshoku of 567, we should discard .
4.4 Building a block
When a hand has fewer than five blocks, we need to build a new
block, possibly from a floating tile we already have in the hand. In
doing so, we should envision the kind of yaku that the hand is going
to have eventually. Consider the following hand. Suppose you are
the dealer and this is East-1. What would you discard?
Č·ffff a %"
As usual, we will split the hand into blocks. Notice that the hand
has at most four blocks only.
Č·ffff| {z }
2
| {z } a| {z } % "
We should thus compare the four floating tiles % " in terms
4.4. BUILDING A BLOCK 105
of their relative capabilities to grow into an independent block. Of
these four tiles, is the strongest candidate, because it can form a
side-wait protorun with two kinds of tiles, and . Any simple tiles
between 3 and 7 are a strong floating tile because of their ability to
form a side-wait protorun. Terminals (1 and 9) will never become
a side-wait protorun, and 2 and 8 can become a side-wait protorun
when paired with only one kind of tiles (3 or 7). However, number
tiles are still stronger than honor tiles because honor tiles can never
form a run.
We should thus choose between the two honor tiles, % and ".
Which one should we discard? Notice that this hand is clearly a
pinfu hand and that it is currently lacking the head. Since value tiles
can never be the head of a pinfu hand, we should discard % rather
than ".
We may want to choose a discard from an existing block rather
than discarding a floating tile in order to enhance the hand value.
Consider the following hand.
Č·Č· a
From a pure perspective of tile efficiency, the discard choice should
be either a or , for discarding either of the three will maximize
tile acceptance. The block configuration behind such a decision is as
follows.
Č·|{z} Č·|{z} | {z } |{z} a| {z }
However, doing so makes it almost inevitable that the hand ends up
having a low score and/or a bad wait. Alternatively, we can expect
106 CHAPTER 4. THE FIVE-BLOCK METHOD
the stretched single shape a to produce two runs, to form
a run, and the tiles in manzu (cracks) to produce one run, as follows.
Č·Č·| {z } | {z } |{z} a| {z }
2
We should thus discard the for now, anticipating to discard the
pair of eventually. That way, we can expect to have tanyao, pinfu,
and possibly sanshoku.
Exercises: building a block
Exercise 12
What would you discard?
How do you divide the hand into tile blocks?
Red
a
4.4. BUILDING A BLOCK 107
Answer 12
| {z } |{z} | {z } | {z } a| {z }
If we were to simply maximize tile acceptance, the discard choice
should be either or . However, that would make the block
in manzu (cracks) too weak. Breaking the or is
not ideal, as these blocks are very strong. We should therefore
discard the to get rid of this edge-wait block. This will tem-
porarily reduce the number of blocks from five to four, but we
can expect to get back to five soon with this hand.
Exercise 13
What would you discard?
How do you divide the hand into tile blocks?
Red
a
108 CHAPTER 4. THE FIVE-BLOCK METHOD
Answer 13
|{z} |{z} | {z }
2
| {z } a| {z }
Discarding or will make this hand 1-Away, so our choice is
between these two options. Notice that the block is weaker
than the other four. As a back up, we should keep two to
maintain the bulging float block in pinzu (dots) for now, hoping
to get two runs out of it. If we draw - or - first, we will
get rid of the block. We should thus discard . If we draw
any of , we should do insta-riichi.
Exercise 14
What would you discard?
How do you divide the hand into tile blocks?
Red
a
4.4. BUILDING A BLOCK 109
Answer 14
| {z }
2
| {z } |{z} a| {z }
As we drew another , the block in manzu (cracks) is now a
decent shape. This can become one group and the head with a
draw of . Therefore, we should discard to break
the bulging float shape.
(Theorymon) Slowbro comes out as gay. Most other pokemon are accepting, but it turns out Ferrothorn is very homophobic. How does this affect the OU meta?
Slowbro has been dating Exeggutor ever since late gen 7, bonding over shared experiences like being Gen 1 pokemon and having weird cousins from other regions. They decide to take it public. Everyone seems fine about it, but Scizor later overhears Ferrothorn talking about how that kind of relationship is āunnaturalā and how ātheyāre not even in the same egg groupā
How is OU affected?
2 Likes
May are you okay
The way I see it, Kyogre is surrounded. Whatās under the ocean? Thatās right, more earth.
1 Like
Chapter 5
Pursuing yaku
This logic is quite flawed. Darkness surrounds light, but light always conquers darkness wherever light is.
the context is that it was an (accidental) reply to the homophobic ferrothorn post that became the most popular in part because it was entirely unrelated to the subject matter
1 Like
Does this mean groudon is basically arctic?
Arcy?
1 Like
They both share similar characteristics
Such as
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hey primal groudon was the best pokemon in ubers during gens 6 and 7
doesnāt really make up for kyogre being the king of ubers in gens 3-5. but.
Well you see may