The Suji Trap

Mastered simple 1-4-7 suji yet? Good, you'll find defending a bit easier once you start using them. Now why don't we test your newfound suji knowledge?

Your opponent just riichi'd throwing away the 5-sou. Now, which among these two tiles would you discard? The 8-sou or the 6-sou?

If you answered 8-sou , then congratulations! You have mastered defending using omote-suji! Too bad you just fed into your opponent's hand, a suji trap.

Suji Traps in a Nutshell

Your opponent had a 5-sou, 7-sou, and 9-sou. He discarded the 5-sou to get you to think that 8-sou was a "safe" tile. Because your opponent decided to declare richii with an undesirable center wait, he managed to get a ron.

Suji traps aren't limited to only center waits though. Pair waits, triple waits, edge waits, basically all single waits are viable waits for trapping people with.

The most common way to make a suji trap is to take the commonly used suji knowledge (1-4-7, 2-5-8, 3-6-9) and discard a tile to deceivingly lead into an opponent discarding the winning tile. For example, if you're going to win on a 9-man, discarding the 6-man (preferably with riichi to alert your opponents) will prompt your opponents to start discarding defensively. If they use suji to defend, they will probably discard the 9-man.

Hand:

In the above hand, riichi-ing and tossing the 6M will cause defensive players to consider discarding the 9M.

Suji Traps vs Regular Hands (Tsumo Wins)

Generally one should go for suji traps if one thinks that he/she will not be able to complete the hand with a tsumo.

Do aim for a suji trap if you feel that a certain player is holding your winning tiles.

Do aim for a suji trap if your winning tile has been discarded twice or thrice, so the chances of you drawing it is unlikely.

Do aim for a suji trap if you want to throw your opponents off. The fact that you produced a trap will make them less confident about their "safe" discards

Do NOT aim for a suji trap if the alternative to one is a possible multi-sided wait where getting a tsumo is a high possibility.

Conclusion

To summarize, suji traps are a great way to throw your opponent off and give an alternative way of winning if you can't draw your tile. Do not aim for I though if you have a high chance of getting a tsumo.

Chombo-王

@nevertenpai

(Tiles courtesy of: http://www.martinpersson.org)

Defending Against Damaten?

Let me say this straight out: It's not easy to do.

You can never be certain whether or not someone's in tenpai with a closed hand unless he or she declares riichi. Damaten is one of the unpredictable things in riichi mahjong. That's why people do it in the first place. If fact, a previous post of mine tells the pros and cons of staying in damaten. 

Disclaimer: If you're going to try to defend against a possible damaten, you should accept that you will bail out and likely will not win that hand. Things like breaking a hand to discard a "safe tile" when someone turns out NOT to be in damaten can and will happen. It's up to you to make the decision whether or not you will continue on the offensive or play defensively.

Anyway, so what now? 

Well you will never be sure when someone is in damaten, but you can probably infer from clues and make an educated guess. I already said it earlier, but inferring that the person in tenpai will not necessarily mean that the person is indeed in tenpai. It's poking at probability, but sometimes you might prefer playing defensively over offensively.

What are the possible "clues" I can look for then?

Essentially it all boils down to your opponents discards. That's right, you have to pay attention to their discards even if they don't call. In fact, if you want to be as sure as possible, you have to observe how fast they discard as well. 

Constant tsumogiri 

Tsumogiri or discarding the tile you immediately drew (most web clients like Tenhou show this). If the player keeps on doing this, and in quick succession as well (i.e. upon drawing, the player discards immediately), then it's an indication that one is in tenpai. In addition to damaten, this is one of the only tells you have for determining whether or not people who call tiles are in tenpai. 

The problem with damaten though is that people tend to gloss over their opponents' discards until he or she calls or declares riichi. 

Of course, there will be some cases where this tell would be too late. There are cases where players get ron'd immediately after one person gets into damaten tenpai. Just to keep in mind though, when someone keeps on discarding the tile they drew, you probably should weigh your options and consider bailing out.

Questionable discards

Alone, this isn't and shouldn't be enough, but if you were to combine this with the first tell, you probably can determine whether or not you should be wary of the person. 

For example, A discarded a 5-sou akadora. Now, you have to ask yourself: why would he discard an akadora? Most people would keep akadoras until at least their hand has finished forming. The fact that A discarded an akadora means that his hand is in tenpai. Now, if he continues to tsumogiri afterwards, well the chances of him being in tenpai just shot up.

---
So that's basically it. I'll list down additional tells I think also can indicate a damaten, but they probably are not as reliable/more situational/only applies to RL. If you want an additional explanation, you're free to contact me.

Hesitation prior to discarding followed by a tsumogiri 
Discarding two out of three of a set in near succession towards the end/middle of the game
Personal tells (i.e. habits your opponent does after getting to tenpai)

Chombo-王

@nevertenpai

An Idiot's Guide to Suji (Omote-Suji)

So upon hearing that some people still aren't that knowledgeable about suji, I've decided to make a very simplistic guide to the most common type of suji, omote-suji. 

Suji is a method that can be used to defend in case there are no sure safe tiles you can discard, well assuming you are trying to play defensively at that point.

Omote-suji is one of the well known suji techniques, and it works most of the time. Plus, it's REALLY simple to remember:

1) Someone discards a 4, 5 or 6.
2) Subtract 3 and take note of that tile.
3) Add 3 and take note of that tile.
4) Those two tiles are most likely safe tiles.

This means that if someone discards a 4, the safe tiles are probably 1 and 7. If someone discards a 5, the safe tiles are probably 2 and 8, and lastly if someone discards a 6, the safe tiles are probably 3 and 9.

1-4-7 || 2-5-8 || 3-6-9

WARNING:
Before you start using suji rampantly, you need to remember that it isn't perfect. It only works if your opponent has a two-sided sequence wait. If you're opponent tries a pair/triplet/center/single wait, it's useless. However, most of the time, people will try for a two-sided sequence wait as it is more efficient for winning, but it has a weakness.

If you have a 5 and 6 in your hand, but discarded 4 earlier, you cannot win on both the 4 and 7 because of furiten. It's the same case with other sequences. This is the weakness of the two-sided sequence wait which makes suji a viable tactic. 

To conclude, suji is a good enough defensive tactic, but don't rely on it too much. If someone is going for an obvious toitoi (all triples), suji will definitely not work on them.

Chombo-王 ‏   
@nevertenpai

Damaten > Other Tactics (Most of the Time)

Let's be honest guys. Who here actually defends prior to somebody calling or declaring riichi? The answer is probably not quite a lot. People tend to concentrate on building their hands until there is a visible sign that someone is in tenpai. Only then do people start playing defensively if they wish to.

Well I'm here to elaborate the main advantages of going for damaten (hidden tenpai) which is basically winning a closed hand, while not declaring riichi. While there are some disadvantages in choosing to remaining damaten (mainly one less han when scoring your hand, or it not working if your hand has no yaku prior to riichi), I believe the advantages far outweigh the disadvantages.

1) Your opponents won't see it coming.

As I mentioned before, damaten is a great way of keeping your opponents in that offensive, "I need to construct my hand" mindset. When you declare riichi people will start discarding defensively, which may hinder you from winning. Having them continue to construct their hands will result in them making those dangerous discards, which will definitely increase the chances of one of them discarding your winning tile. They'll definitely be surprised when that happens.

2) You can choose to bail out any time.

Think of this situation: You riichi'd on the fifth turn with a two sided wait. Fair enough, right? Well after you riichi'd, the guy in front of you called Chun (red dragon). Moments later, he called Haku (white dragon), and then it happened. You drew Hatsu (green dragon). By virtue of your riichi, you are forced to discard that tile, yet by doing so you are probably feeding into a Daisangen (great three dragons). (You could always try to chombo to avoid paying up, not that it'll work in online clients.) Now, if you were in damaten instead, you could have bailed and chosen to discard a safe tile. Not getting an additional one han sure beats having to pay a yakuman.

3) You can improve your hand and waits while waiting for your winning tile.

Imagine you have this hand: (Round: East 3, Seat: West, Dora: 9S)

1M-1M-4M-6M 3P-4P-5P 3S-4S-5S E-E-E

 

Your current winning tile is a 5M. Assuming you riichi and get an ippatsu ron (ron within one go around after riichi), you would have three han unless you get uradora (riichi, ippatsu, yakuhai) resulting in 5200 points. Note that this situation is nigh impossible as well due to the fact that you're waiting on a single tile.

Now what if you didn't declare riichi? You would still win albeit with lower points if someone discarded or you drew a 5M, but at the same time, you can choose to improve your waits. What if you drew an akadora for one of your 5's that you've been waiting on? What if you drew a 3M? If you had riichi'd, you would be forced to discard the 3M, but if didn't, you could have improved your hand significantly.

(Round: East 3, Seat: West, Dora: 9S)

1M-1M-3M-4M 3P-4P-5P 3S-4S-5S(akadora) E-E-E

That hand value if someone discards the same 5M is worth 4 han now, 8000 points (sanshoku doujun, yakuhai, akadora). You also improved your waits from a single to a double sided one. Plus you have the element of "surprise" with you (as discussed in no. 1)

4) Once you start using it, people will get paranoid.

Imagine winning two hands straight by virtue of damaten. At that point, people will probably start to be wary of your hand and discards. "Is he/she tenpai yet?" "Is this tile safe?" "Do I bail out now since I think he's about to win?" This will essentially make it more difficult for them to form their hands. By the time you reach tenpai, they probably will have sacrificed a high scoring hand for something more safe. Of course, since damaten hands are usually cheaper than riichi'd hands, some people will continue to play their usual game. Don't underestimate the power of damaten though. Damaten sanbaimans and kazoe-yakumans do exist.

 ---

Now even after saying all of that, I still somewhat believe that declaring riichi in some situations is better than being in damaten. (A double riichi is an example of that, or when you're in last place and need to catch up.) In other situations, calling tiles for a cheap win (yakuhai) or an expensive one (chiinitsu/honitsu) is also better. 

I still have to say though, damaten > other tactics all most of the time.

Chombo-王

@nevertenpai

The Intentional Chombo: A Valid Tactic?

Let’s talk about something possibly “controversial”. I’d wager that if you were to do this in a pro match and get caught, you would probably be kicked out. I’m talking about the intentional chombo.

In case you don’t know what a chombo is, a chombo is a severe penalty that is given as a result of a major violation. The unlucky soul who gets it has to pay out a relatively large amount of points to the other players: 8,000 points, worth a mangan (note that a dealer has to pay a dealer’s mangan worth 12,000 points). After he or she pays out, the round will get restarted. This means that if the offender chombo’d in East 4, the round will remain East 4.

(Violations that may result in a chombo include invalidly claiming a winning hand, calling a win on furiten, destroying part of the wall, etc.)

Now you may be asking, “Why the hell would I want to chombo intentionally? I lose points and the round doesn’t even move forward!”

To those who only play online, you need not worry about this. Popular clients such as Tenhou will not allow the player to chombo at all. However, if you play IRL and are interested, the answer to that is actually very simple.

Imagine you’re playing, and someone discarded idiotically, so now your opponent has this hand:

? NNN EEE SSS WWW

*for this game, we assume the “responsible one pays” rule is inactive.

Well, I have to say that you’re screwed. Daisushi (great four winds) with a single wait on an unknown tile? You better hope that you have enough safe tiles to discard, or else you will be playing blindly. There’s also a chance that the player will shift waits in order to confuse you. Not to mention, the possibility of a tsumo.

So what now? You can try to play fast and get a cheap hand, or maybe feed into someone else’s cheap hand. But playing offensively presents a huge risk of losing 32,000 to 48,000 points. So now we come to an impasse: Paying a mangan beats having to pay a yakuman!

“I can intentionally chombo to prevent this guy from winning this round!”

Now once again, I would like to say that doing this in tournaments would be considered unsportsmanlike play, and attempts to chombo intentionally should probably be reserved for games with friends. Even then it’s a downer to do. You probably can pass it off as a “brain fart” once in a while, but do it too much, and it gets suspicious.

Not to mention, most people would probably just continue to discard safely and hope that the player won’t win that hand.

But hey that’s just my opinion. At least you probably haven’t attempted a false double riichi…

Chombo-王

@nevertenpai