Half Flushes, Part 2

We continue this week with xKime’s translation of Puyo’s blogs. We also have professional input from JPML’s Garthe Nelson, adding to the depth of the conversation. Hopefully some of these issues will bring some good conversation to the forums as well.
From: http://blog.jpmahjong.net/read.php/525.htm

Last time we talked about situations where you mustn’t aim for a flush hand, so in what situations can we aim for a half flush? Naturally, one of the factors is the amount of tiles in a suit, but there are many other factors we must keep in mind as well:

1) Times when it’s hard to keep a concealed hand
A non-concealed half flush is downgraded from 3 HP to 2 HP, but if you can pursue a concealed hand that difference is mostly overcome because you can reach. If you get One Shot and hidden dora, the difference is even greater. If you’re thinking about going for a half flush in a suit that’s not the dora suit, then it’s worth thinking it over one more time.

dora: 5d

If you don’t have dora it’s not necessarily bad to go for a half flush. On the other hand, if you have one dora, you can’t just jump into a half flush. In this example hand you must discard the red dragon.
After you discard the red dragon, not accounting for the 6 of dots Ready/tenpai (because you would have to discard the dora), there are 34 tiles that will get you to tenpai, and also when you get there it will definitely be a good shape. It’s simple to go for a concealed hand and win. It’s important to know, with reach, concealed self draw and a hidden dora this hand is already a Mangan (8000-12000pts).

If you force your way into a half flush tenpai, ninety percent of the time it will be a 2600 points tenpai. Very different; it’s a lot better to keep a concealed hand.

2) Your half flush tiles have good shape or the tiles you need are very easy to call from other players
When you go for a half flush the tiles you can use to improve your hand are, naturally, very few, and also the player to your left can keep the tiles you need, therefore we can’t afford to make a mistake with our hand shape. If you have good shapes like the 3445 shape we mentioned before it’s a good start. If the non-half flush alternative has a better shape than a half flush, we must once again consider whether to continue going for a half flush is best or not.

Furthermore, because making a half flush may require calling tiles, paired tiles that are not so useful for a concealed hand, become really useful because you’re able to pon them from any player. Tiles like 1,2, 8 and 9 are especially easier to call; when you’re constructing a concealed hand they can be tough, but when you go for a half flush they are very useful tiles.


In this hand you can discard the 8 of bamboos first, retaining the red dragon as a possibility to make a half flush.
The shape in dots and bamboos is not good, plus we have the 118899 in characters/craks. Those three pairs are very useful, we’ll find many hardships in the concealed path. But if you aim for a half flush, because 1, 8 and 9 are easy to pon, you can still win this hand, and with a little luck it might even be possible to complete a full flush.

3) Value tiles
Value tiles are very important and the most common hand combination with half flushes. Just having value tiles gives you a great reason to go for a half flush. There are three good reasons:
1. Value tiles can improve the score of the half flush
2. Value tiles are easy to pon, but hard to complete a set within a concealed hand.
3. When you pon a value tile, you need less suited tiles for your half flush.

That’s why there is a maxim in Japanese mahjong that goes “When you have two pairs of value tiles, go for a half flush”.

4) There’s no other choice but going for half flush
In some hands, aiming for a half flush isn’t just to win the hand.

If you’re in a point situation where you don’t really need to win the hand, Discard the 9 of characters here (or even the 4 of characters) and force your way to a half flush.
Aiming for a concealed reach hand with this hand is complicated enough, and the final score isn’t big either. Since it’s difficult to score a win already, do not use up all of the tiles in your hand. Here, deliberately discarding middle tiles early, along with calling a tile of your half flush suit from another player, is not a bad trap.
If you can draw a few bamboo tiles afterward, you might be able to actually complete a real half flush. Even if you don’t, you can put some threat and pressure on the player to your left. This is the most common type of “bluff” in Japanese mahjong. However, be careful. If after a few discards the shape of the hand is still not good, you cannot continue calling tiles, and you must store a good amount of safe tiles for defense purposes.

We have spoken about most of the necessary conditions for a half flush, in the next section we’ll be talking about how to handle specific situations.

Note: This ends the “beginner” part of this series of articles, and thus we will now be continuing with articles from the “intermediate” section.

Commentary from Garthe Nelson.

A Half Flush is worth more points than other hands because it’s harder to win.

Try not to slide past that point: it’s HARDER to win.

For that reason, I think a lot of strong players choose not to aim for this hand even when it’s a viable option. Or at least they don’t go for it straight off. Look at this hand:


It’s a pretty good candidate for a Half Flush, but I have seen a lot of players throw the 1c in this sort of situation. The reason is that it will make other players much less suspicious to see those middle tiles in other suits come out of their hands after something in the Half Flush suit. Thus it might not be as hard as usual to win the hand because of the increased possibility that other players will throw useful tiles or even the winner.

If they get something in the other suits creating an open-ended wait, well, that’s the direction the hand went, and to continue pushing for the Flush is not likely a winning strategy.

I doubt they even feel like it’s such a loss if after throwing 1c, it would have paired or even tripled up. Having thrown those other middle tiles early and then finally letting go of something in the flush suit, other players will be immediately tipped off. They’ll be careful with that suit and the value tiles too.

Really, the more I think about it, the less I recall seeing many Half Flush hands (besides mine) in our study sessions. I think strong players (in contrast to me) must assume that given the obviousness of the danger zone to other players, it just tends not to be worth it.

Hmmmm, I hope you learn as much reading this stuff as I do writing it.

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