Riichi and Defensive Play

It has been awhile!

After a brief hiatus (2 years?), I have decided to start writing fairly regularly for this blog. Hopefully it can generate some interesting discussions about Riichi strategy.

Most people I encounter have started playing Riichi Mahjong because of watching the (excellent) anime Akagi, Saki, or Legendary Gambler Tetsuya (or all three). Because of this, I believe that going through some strategic themes in individual episodes would be helpful.

By the way, to anyone reading this blog... if you haven't discovered the greatest Riichi website online yet... here you go...

http://tenhou.net/0/

It's free. It's fun. It's fast. Only problem is that it is entirely in Japanese, which I do not read. However, I still play on here--it is fairly simple to learn how to play. Here is an english guide to this great website.

http://arcturus.su/tenhou/

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Onto a little discussion.
I am currently rebuilding my tenhou account under the name Tyche. I used to be playing at the 2 dan level on the public servers on tenhou... but college graduation, etc. have interfered with my riichi playing. Some of my future posts will probably be referring to games I play under that handle.

In my last post (2 years ago), I mainly discussed the tension between luck and skill in Riichi. For today I will start discussing defensive strategy. Since I am by no means a great player, anyone's input or feedback will be helpful. However this blog will assume that the reader is at least somewhat familiar with the terminology of Riichi Mahjong. You can learn how to play, and learn the terminology at: http://www.delfosse.com/mahjong.html


First let's talk about what "offense" and "defense" mean in Riichi Mahjong.

When I say offensive play, I mean that you are heading for tenpai as fast as you can, with no or little regard for the discards you are making. You might keep dora in your hand, or different aspects of a yaku present in your hand, but for the most part you discard whatever does not help you. As I mentioned earlier, this is probably what you want to be doing, as long as you start out at least 4 or 5 Shan Ten (i.e. 5 discards away from tenpai).

When I talk about "rules," I am only talking about rules of thumb that I have devised through my experience playing. If anyone has any objections to them, please let me know your logic. Some rules for offensive play follow, in order of importance.

1) Head for tenpai as fast as humanly possible**
2) Discard terminals (1s and 9s) and honors that you cannot use
3) Discard in a manner that gives you the highest probability of reaching tenpai.
4) Keep track of your outs and whether they are being discarded or not.
5) Keep track of the status of other people's hands and discards.

**- this is subject to the status of the game, and how many points you need to win... but I will talk about this more later

I will discuss offensive strategy in more depth in a later post, but I am open to discussing any of these points.

By defensive play, I mean that you are not playing to win. This occurs in 2 main circumstances.

1) You started out the hand 5+ Shan Ten
2) You have been playing aggressively, but for one reason or another someone else's hand is faster or too large to play against.

Both of these circumstances occur frequently.
The first circumstance (I call it a "dud hand") is usually easy to play so that you do not lose... you play for a draw.
The second circumstance (unlucky draws, or SOL) is somewhat trickier since you haven't been planning on this style of play from the beginning. This kind of circumstance will take more insight, more guesswork, and more skill to play.

First off... why play defensive? So what if your hand is 6 Shan Ten from the start? Why not just try anyways! This is a game of luck, right? So if you get lucky, you win!

The problem is... if you play 6 Shan Ten hands aggressively against good players... the vast majority of times you are going to lose. Even if you don't play into another's hand, you will not win. So why increase your losing percentage? Why give other players more luck than they already have? Why discard a dora when you're 4 away from tenpai so that your friend can call a kan of dora, draw a tsumo off the deadwall, get a baiman and win the whole game?

Also, if you are 2 away from tenpai, someone calls riichi, and the best hand you can possibly muster would only win 2 or 3 fan if you got REALLY lucky... why would you play aggressively and possibly play into the East Wind's multi-sided mangan wait?

In short, unless you're masochistic, you need to learn how to play defensively. Otherwise you will notice that you get 4th place a lot (even if you get 1st a lot as well!).

Here are my rules for defensive hands so far, in order of importance.

1) Do NOT discard dora, dragons, or winds that can help your opponents win or get larger hands.
2) Pay strict attention to the other player's pools. Try to figure out what each player is going for so that you do not discard what they need for calls. This rule helps you accomplish rule 5, since you can't know what tiles are safe if you do not look.
3) As a rule of thumb, do NOT discard 7's or 3's
4) Early on, discard "middle numbers" (i.e. 2-8), not terminals.
5) Try to stockpile safe tiles. These are your lifeblood.
6) If someone reaches, or calls a pon of dora, or looks like he/she's in tenpai... start playing the safest tiles you possibly can.

Explanation of these rules:
1) Do NOT discard dora, dragons, or winds
This rule is pretty straightforward. Giving others the chance to call doras, dragons, or winds help your opponents get yaku and fan. Since you are not playing to win, giving your opponents yaku and fan will let their hands develop faster and get larger. We don't want that.

Let me clarify concerning dragons and winds. If you are playing totally defensively from a dud hand (i.e. from the beginning), do NOT discard dragons or winds at all--even when other people discard them!

Why? Think about later on in the game, when you are facing a riichi to your left, and a player who called a kan of dora to your right. What kind of tiles will you want to discard then? How about those 100% safe dragon and wind tiles that they discarded earlier!?

2) Pay strict attention to the other player's pools
Pool awareness is difficult, and solid rules of thumb are sometimes difficult to prescribe. One helpful hint is that terminal discards and honor discards will not tell you very much at all about someone's hand, since they are the least useful single tiles that people can hold (since they either don't connect in runs [i.e. honors] or they only connect to one run [i.e. terminals]).

One other rule I'm playing with is the "Plus 3" Rule. Plus 3 Rule is not a strict rule, but it works most of the time. The Plus 3 Rule says that if an opponent discards a tile, it is likely that the tiles 3 away from it are also safe.

Why? Think about this. If you have a hand that is tenpai after your next discard, and you have 3-4-6... you are likely going to discard the 6 to get a two sided wait on 2's and 5's. Let's say you riichi after you discard your 6. Your opponents can probably assume that 9's and 3's are completely safe to discard.

This is because 6 is an out for 2 different two-sided waits (4-5 and 7-8). These are called "suji" in Japanese--the two tiles on the sides of a two-sided wait.

So as long as your opponents can safely assume that you are making a two sided wait, then 3's and 9's are perfectly safe as well, since they are suji. In this scenario, 9's are especially safe since they are both suji to 6's and also terminals... so it is impossible for you to win off 9's as part of a 7-8 two-sided chi wait (because of the furiten rule).

However, the key part of the 3-Plus Rule is that you must assume that your opponent made a two sided wait, which is not the case sometimes. Consider this:
Player X has tenpai after this discard, and has 4-6-8. X discards a 4 and declares riichi.

Player X has a single wait on 7's and the 3-Plus Rule would make you discard straight into X's hand.

However, it is bad to discard a tile and wait on the other suji since it is a single wait. That means only 4 tiles will let you win, assuming none of them are discarded, used in others' hands, or in the dead wall. In all likelihood, a single wait actually has only 2 or 1 outs.

Of course there are some obvious things to notice. If someone is only discarding man (character) and sou (bamboo) tiles, you can probably assume that they are making a Honroutou (dirty flush) or a Chiniisou (Pure Flush)... so avoid discarding that suit.

One last piece of advice... pay extra attention to the player on your right since he/she can call chi's from you.

I will talk more about this rule in later posts, but if anyone has anything in particular they would like to discuss, please feel free to tell me.

3) As a rule of thumb, do not discard 7's or 3's
This is because 7's and 3's are crucial tiles for one chi (7-8-9 for 7's, 1-2-3 for 3's) and also part of 2 other middle chi (5-6-7 and 6-7-8 for 7's, 3-4-5 and 2-3-4 for 3's). By keeping 7's and 3's, you slow down other hands or stop them completely if they are waiting with 8-9 or 1-2.

4) Early on, discard middle numbers and not terminals
This relates to Rule 5. You want to stockpile safe tiles. But you have to get rid of one tile every turn. So what tiles should you get rid of early on? The ones other players will win off of later!

The most common tiles people can win off of are middle number (2-8) tiles. So get rid of these. You can even get rid of 7's and 3's as long as you think that the player to your right isn't going to call them.

The earlier the better. Early on, players usually do not want to commit to calling since it will Open their hand and eliminate Riichi for the rest of the hand. So early on risky tiles are the best to discard.

Around the middle of the 2nd row of discards (assuming no one has declared riichi and no one looks like they're going out soon), you should start playing it safer. But judge it for yourself.

5) Stockpile safe tiles.

Look at the pool. Find safe tiles. Stockpile them for when the middle of the 2nd row occurs (when most good players hit tenpai) so that you can survive to the end of the round.

One important thing is to find the Hero Hand, as I call it. The Hero Hand is the guy who will win big if he wins. Sometimes this is very obvious, if someone has a Kan of dora tiles, or has 2 pons of dragon tiles, etc. But sometimes it is the silent riichi early on the 2nd row that you must be afraid of.

6) When tenpai strikes, play safe tiles
When someone declares riichi, or is suspicious, or has called 2 or 3 times... you should start playing safe discards.

Safe discards come in different rankings based on how safe they are. The best are 100% safe tiles. These are tiles that are present in the pool of the person you are "playing against" (i.e. the person in tenpai).

Then things get a little tricky and involve some pool reading. One can use some rules of thumb like the 3-Plus Rule if one needs to. Other mostly-safe tiles like winds and dragons that have already been discarded by other players should be good here too (unless the Hero is very, very tricky!).

Worst case scenario is when it's your turn, you have no idea what tiles are safe or not, you're facing a huge riichi to your right, and you are not playing to win in the first place. If you can't use the 3-Plus Rule, I would recommend guessing what your opponent has based off his discards, betting on that guess, and throwing a prayer into the pool. However, if you have been playing defensively since turn 1, you should have stockpiled enough safe tiles by now that this sort of scenario does not occur often.
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Thanks for reading this short article on Defensive Play theory! Please send me suggestions, comments, criticisms, or references in the Comments section of the blog or directly to me at gankles(at)gmail.com.

Thanks for helping the English-speaking Riichi community learn more about this chaotic and fun game!

Tyche