How to improve your mahjong skills: Push/fold decisions (for beginners)

① Decision to push or pull
② Ori's technology
③ Techniques for making noises
(④ Tile efficiency)
This time, I'd like to write about point ①, deciding whether to push or pull.

By the way, this page is written for beginners. There are many excellent strategy books that discuss precise push-and-pull decisions, so I will leave that to those.
(Books by Nemata and Fukuchi)
Here, I will try to explain things as simply and clearly as possible so that beginners can easily put them into practice.

Push and pull

Last time, I wrote that the following points are important for becoming a better mahjong player.
First, let's start with the question, "What is 'push and pull'?"
In mahjong, "pushing and pulling" refers to deciding what to do when your opponent is on the offensive.

The following information is generally important when deciding whether to push or pull:

① Whether the opponent is in a ready hand (tenpai) state, and whether the opponent seems to have a high score.
② This checks whether the player is in a ready hand, whether the waiting tiles are good or bad, and whether the score is high.
③ The score difference between you and your opponent, and which game it is.

Let's consider these three points in order.

Whether the opponent is in a ready hand or not, whether the opponent seems to have a high score or not.

This is clearly evident if your opponent has reached a winning hand.
However, it's tricky when the opponent is calling out.
In that case, if it's the 12th turn after the first call, the 10th turn after the second call, or the 8th turn or later after the third call, you can assume that your opponent is in a ready hand.

And when it comes to judging whether someone is likely to score highly, the important factor is whether they are a parent or a child.
If you're unsure, a good rule of thumb is that a dealer's reach is worth around 9,000 to 10,000 points on average, while a non-dealer's reach is worth around 5,000 to 6,500 points.
(In the case of the rule with four red tiles)

If the opponent makes a sound, it becomes easier to deduce.
You can deduce things like honor tiles, flush hands, simple hands, and the number of dora tiles from the tiles you can see.

Whether I'm in a ready hand, whether the waiting tiles are good or bad, and whether the score is high.

This is quite important, and it might be difficult for beginners to develop this sense.
It's painful to give up halfway through when you've worked so hard to get to a winning hand from the initial deal.
However, the fate of mahjong is that once your opponent takes the initiative, you pretty much have to give up.
However, if you are also in a ready hand, the opportunities to push increase significantly.

First, if you have a good hand, you can push forward if you have about half the points of your opponent.
In other words, if you estimate your opponent's dealer's reach to be around 9000 points, then having a good hand worth 3900 points plus your opponent's reach stick would be a reasonable way to push.

And if you estimate the opponent's reach is worth around 5000 points, then if you have a good hand worth 2000 points plus the opponent's reach stick, then you might be able to push this one too.

Next, if you have a bad hand shape, you will need to score about the same number of points as your opponent.
When facing a dealer's reach, you'll need around 8000 points in a bad hand, and when facing a non-dealer's reach, you'll want around 5200 points in a bad hand.

However, if you're only one step away from a winning hand, it's almost always difficult to push.
If you're going to push, it's only going to be a tough one unless you have a hand that's worth over 8000 points, with plenty of possible winning hands, like a perfect one-shanten or a double ryanmen.
————————————————————————————————

Double ryangmen is one step below a perfect one-shanten,
Example: 11 34 78 ? *** *** (? = safe bet, etc.)
This strategy involves discarding the possibility of forming a triplet and instead holding onto one safe tile.
This is a state where you want to secure a Pinfu (a type of winning hand in mahjong) or hold onto a safe tile to be able to respond to a Riichi (a declared hand in mahjong), prioritizing a bit more defensiveness.

The score difference between you and your opponent, the game number, etc.

To put it in extreme terms, if you're in the lead in the final round, there's absolutely no need to push against the person who's overwhelmingly in last place and has declared a reach.
Similarly, when facing a lower-ranked player with a reach, I recommend playing with a slightly defensive approach.
For those at a lower rank, it's a welcome thing when those at a higher rank challenge them, because it puts them on the same playing field.

Furthermore, the further the game progresses, the better it is to adopt a defensive stance.
In the East round, you should try to accumulate some points, but in the South round, I recommend playing more defensively.
Within a single game, the further the turn progresses, the higher the likelihood of a draw.
In that situation, the chances of winning by pushing become lower, so there are more situations where pulling back is more advantageous.
To summarize the general principles of pushing or folding against an opponent who has a ready hand, it would be as follows:

My opponent has reached tenpai!
- Before your hand is two steps away from a winning hand
Almost entirely original.

- My hand is one step away from a winning hand.
If it's before the 10th turn, and you have 8000 points or more, and you don't have a perfect one-shanten or a double ryanmen or better, fold.

I'm also in a ready hand.
If it's a two-sided sequence, is it a move that gives you half the opponent's points?
If it's a bad shape, is it a move worth the same points as the opponent's?
If not available, use Ori.

In short, that's the gist of it.
These are very rough indicators, but I tried to make them easy to understand and use even for beginners.
Once you reach an intermediate level, you should focus on improving your precision.

実践例で確認する押し引き

ここまでの目安を、実際の場面に当てはめて確認してみます。
初心者のうちは、目安を知っていても、実戦でとっさに判断するのは難しいものです。
簡単な例を3つほど挙げてみます。

ケース1　8順目、親リーチに対して良形1シャンテン

8順目に、親からリーチが来たとします。
親のリーチなので、点数は9000点前後と見積もっておきます。
こちらは良形の1シャンテンで、上がれば3900点ほど見込めるとします。
先ほどの目安では、良形なら相手の点数の半分くらいあれば押せるという話でした。
親リーチの9000点の半分は4500点ほどなので、3900点は少し届いていません。
ただ、8順目とまだ早い巡目で、受け入れの広いダブルリャンメン以上の1シャンテンなら、無理に降りるほどではないという判断になります。
点数がぎりぎり届いていなくても、巡目の早さと受け入れの広さを加味して押すかどうかを決めていく、という一例です。

ケース2　南3局、子リーチに対して2シャンテン

南3局で、対面から子のリーチが来たとします。
子のリーチなので、5000点前後と見積もっておきます。
こちらはまだ2シャンテンだったとします。
目安の通り、2シャンテン以前はほぼオリという判断になります。
たとえ手牌の点数が高くなりそうでも、2シャンテンからテンパイを取りに行くのは、通常はリスクに見合いません。
南場という終盤の局面も踏まえると、なおさら大人しく降りるのが無難という結論になります。

ケース3　良形テンパイでも、相手の点数次第で判断は変わる

自分が良形でテンパイしていて、上がれば2000点ほど見込めるとします。
そこに親からリーチが来て、しかも捨て牌から役牌・ドラ3くらいの高い手が疑われるとします。
良形テンパイだからといって、反射的に押すのは危険です。
相手が倍満クラス（16000点）を想定しているなら、その半分の8000点は必要ですが、自分の手は2000点しかありません。
このように、良形かどうかだけでなく、実際に相手の点数をきちんと見積もることが、押し引き判断では欠かせません。

以上のように、巡目・シャンテン数・待ちの形・相手の点数見積もりを組み合わせて判断していくのが、押し引きの基本的な考え方です。