Why we do open on Tengen

Here will lie useful information about opening on Tengen. Feel free to add what you think should be added. See also Tengen.

Clearly, on a 9x9 board (and smaller) the tengen opening is very strong. Black can play here and claim the side opposite his opponent, as well as their center. Most of the time at 9x9 I, Daniel-chan, open here.

On larger boards it is really a speculative play, for example the 19x19 tengen openings. I don't think I'd play it as White, though I can see that, with komi, it might be workable. To me, a tengen opening makes more sense as Black, at least at my level (beginner), since through will often claim the corners, so the corners develop evenly (at least at first). I don't do it even on 13x13 boards, but who knows? Perhaps I will become adventurous :)

-- The editor formerly known as Daniel-chan :)

I have opened successfully on Tengen on 19x19 on several occasions. Focusing on influence pointing towards the middle is a huge point in playing these games. I usually try high approaches instead of low, for example. -- FFLaguna

Anonymous: I open on Tengen about 1/3 of the time I play Black. I have no idea if it's the 'best' move or not, and frankly I don't think it matters for us amateurs; tengen leads to interesting games that are difficult for both sides, often a conceptual clash between influence and territory, and at my level (9k* IGS) I can't ask much more from an opening move.

anonymous: A common rule about tengen is "When the situation is symetric (all-board speaking), you can play the tengen." That, obviously, includes black's first move.

Alex: For players fond of fighting joseki, such as the taisha joseki, the large avalanche and the magic sword, tengen can be a good opening move because it breaks ladders for all four corners at once. I wouldn't recommend it if you're playing a reasonable opponent, however, as it's easy to avoid fighting/ladder-dependent joseki if one isn't too greedy.

I think tengen can be almost as good an opening move (shouldn't lose more than one point, say) as komoku/hoshi, but requires a lot more knowledge of fuseki theory to play properly than a more normal move. Unfortunately, most of the people I've seen play tengen play it precisely because they don't understand the fuseki, and consequently tend to get terrible positions going into the middle game when playing against opponents who do.

Binky: I am a humble double digit kyu player and my declining powers of analysis reflect my growing age. I am not Einstein, but I can understand the implications of the theory of relativity. Similarly, I am not a Dan player, but would be interested to hear the views of better players than me on these points....

My experience of playing tengen openings over the last six months, mainly against players of strength/weakness equal to me, produced the following tentative thoughts:

1. with practice, this has not weakened my play

Chris Hayashida: I wouldn't expect it to.

2. my strategy has been to use the tengen stone for any these purposes:

• as a breaker for many ladders possible from all four corners,

• as a stone to run, escape, aim or connect to from anywhere on the board,

• as part of a potential moyo including anywhere on the board,

• as bait for my opponent to capture (causing loss of sente),

Chris Hayashida: This would be a mistake by your opponent.

• as an antidote to people who mindlessly follow learned joseki,

Chris Hayashida: This is also relying on an opponent's mistake.

• because there are so few serious studies of it (in English);

of course flexibility is a keynote to playing Go well.

3. I am not impressed by the "loss of sente" argument. Of course I lose the first move in one corner, BUT

• sente is expected to change many times in the course of a game,

• sente is lost once, it is not lost in all four corners,

• tengen's influence everywhere, more than makes up for an initial loss of sente.

Chris Hayashida: I agree with your points on sente, however, I disagree with your analysis. Part of the advantage of playing Black is that you move first. This, in turn, is being offset by komi. If you are not getting full value for your move (be it 6.5, 7.5, or however many points) than you may be losing ground when playing the first move on tengen. Is the influence from tengen worth 6.5 points? 7.5 points? I think this is part of the problem when trying to argue for or against opening on the tengen.

binky? Apologies - I omitted to discuss the komi point. If tengen's influence limits your opponent's choices of joseki, is it not conceivable that it is worth 2.5 points in every corner? Perhaps another point for every side? Total, 10 to 14 point compensation for loss of 6.5 or 7.5 komi. I'm too weak to understand the value of influence...

Chris Hayashida: Don't feel bad, I think the pros can't either. That's part of why they say it's a hard opening to play and judge, because there are too many possibilities. :)

4. The best defense usually seems to be a kakari play in the vicinity of the tengen stone. This can annihilate most of its influence or at least halve it.

Chris Hayashida: I suspect this is also showing part of the issue... You may have problems yourself if you play White and your opponent opens on tengen. Note that it is possible to play a more "normal" game, but expand faster as White if Black plays on tengen, and win by creating more territory. Black, on the other hand, may end up having to reduce territory from the tengen. If you can create more territory than Black can take away, you may be able to beat play at the tengen.

5. To tenuki tengen is no different from making a tenuki in any corner opening.???

Chris Hayashida: This feels wrong, even if I can't really justify it. It seems like a tenuki in a corner will sway the balance more than if one tenukis in the middle. For one, there is less room in the corner to run away...

6. I do not have to play high or lightly. After playing tengen, I find many opponents try to block me from connecting to it by pressing me down. That makes it easier for me to take territory at the corners and edges. Moreover, the tengen stone often nullifies or weakens the strength of their walls.

Chris Hayashida: This also sounds like a strategic error by your opponent. They shouldn't be pushing you down if they don't get anything from the wall they are building.

7. Some opponents have researched tengen and try to stop me from getting the "Great Wall of China", so I tell them I am building "Offa�s Dyke" instead.

8. Tengen is regarded my many as a wasted move. If so, it is definitely less of a handicap than giving your opponent a single handicap stone; because it is your stone - and it is there.

Chris Hayashida: Sure, but you're forgetting about komi.

9. To say don't follow tengen with 3-3 point because it gives Black the 4-4 point which coordinates with tengen, is illogical. Surely it is equally true to say, don't follow tengen with 4-4 point because it gives Black the 5-5 point which coordinates with tengen, or even, "don't play anywhere on the board because it allows your opponent to play somewhere else which coordinates with tengen"???

Chris Hayashida: This claim is based on the idea that pushing along the 3rd and 4th line is considered close to equal for both sides. I don't think that playing the 3-3 point is good after playing tengen. My argument is that it is hard to develop territory. Playing the shoulder hit (especially right away) against the 3-3 may be the wrong move, but it is another move that can effectively destroy any potential territory made between the 3-3 and tengen stones. If he plays a shoulder hit against a 4-4 stone, it is possible that the corner can be solidified into significantly more territory.

I'd be interested to see the dan players' responses.

Chris Hayashida: I think that opening at tengen is novel. I am not telling you to stop. But at the same time, I found it was better (for me) to play more "traditional" openings, so that I would have a more manageable game in the opening and middle game. When I played games opening at the tengen, the games tended to be more wild, with lots of running groups and fighting. I decided it was better (for me) to hone my skills and judgment by playing moves with easier-to-understand concepts.

While your opponents may be playing joseki blindly, or not finding a counter to your opening easily, does that really help your game? Are you relying on an opponent's weakness? I shy away from this, in the same way I don't try to use "trick" joseki. I don't think opening at tengen is a bad move, and I'm sure it deserves more research, but I think there are other parts of my game which require much more work, and probably are much easier to study. Hope this helps.

sjd123 I sometimes open at the 5,5 point, 4,5 point, then 14,9 point. I didn't seriously think it would be any good at first, but I beat someone one rank lower than me when I tried it, so I still play like that sometimes. I expect a dan player would punish me for it, but its still fun...

binky? Thank you for your responses Chris, although your insertions rather break up the flow of my text.

Re my points under 2. above:- I believe all my wins have resulted from my opponent's weaknesses - and all my losses upon my own. I learned to "punish" my opponents mistakes. That includes exploiting the other's mindless use of joseki, their failure to read the big picture, their fear of complex fights, their bad shape, their inflexibility and their blind adherence to tradition.

Chris Hayashida: Well, I suppose all games are lost on your opponent's mistakes. I just hope that you aren't using your opponent's mistakes as justification for the strength of the tengen opening.

A "bait" is another word for a 'sacrifice' 'stone'. Sacrifice is a well established technique in Go. Sometimes your best moves are found in your opponent's lid. Look at the http://mignon.ddo.jp/assembly/mignon/go_kisi/dosaku_shunkai.html tengen game, particularly moves 158 to 166 around the tengen stone, up to the capture at 238. Did black not sacrifice the stone? Who profited from whose weakness?

Chris Hayashida: While I am not familiar with this game, I suspect that move 158 is a reducing move in the middle game, and not an opening move. As a result, I suspect that the purpose of the move is to reduce territory. Even if the stone itself is captured, it probably served its purpose to reduce potential territory. In the opening, it is usually a mistake to play moves to capture stones tightly. Usually making moves which map out potential territory can be much bigger.

Re my point at 5. above:- I can find little assistance about defences against tengen. I would be delighted if more opponents used it to enable me to explore its meaning. Most analyses of joseki are (by definition) corner based and the study of joseki has dominated thinking about Go for too long.

I have tried to help others to think about using and countering the tengen opening (or other centrally based openings) and only wish it was given as much attention as joseki. Of course fuseki study is more helpful.

Chris Hayashida: Fuseki study is important, but I think that good strategic fundamentals in the middle game will give you more bang for your buck. Middle game fundamentals overlap with fuseki theory, so I don't think it would be wasted study. What's more, since middle game theory is more generalized, I think it will be more useful than studying specific openings, such as the tengen, the Chinese fuseki, or the San Ren Sei. A big reason that joseki is studied more than fuseki is that joseki are used as building blocks for fuseki theory. If someone is blindly playing joseki, then that person doesn't truly understand them. Anyway, I hope this helps, and I wish you the best of luck in your studies.

Richard Cant - I don't think middle game strategy is anything other than working through the consequences of Fuseki strategy. Someone who plays a good fuseki - but then fails in the middle game doesn't understand why their Fuseki was good in the first place. Unless of course it was a tactical error (bad reading) that caused the problem.

Also see why don't we open at tengen...

        Tengen fuseki