Question for experienced players: Is this a thing? (Sideseki?)

I was thinking about a fuseki strategy lately that would have been based mainly on ignoring the corners and playing on the side star points. The idea came about when I noticed that most approach josekis (moves designed to provide a balanced/fair result for both players) involve some kind of extension towards the side to settle the approaching group. Therefore, the idea is that if I already have all the sides, I can approach all the corners while keeping sente.

Here is what I am thinking about.
In example 1, let’s say that the opponent plays a 3-4, then you can approach it from every side and keep sente:

In example 2, let’s say that the opponent plays a 4-4, then you can invade it, keep sente and have the side stones already in place to harass the white walls

In example 3, let’s say that the opponent plays a 4-4, Black invades and White decides to keep the corners. Then the side stones are already in place to extend the result and keep sente:

Of course, the opponent will not play just 3-4 or 4-4 all the way or they might even play something else and a realistic board might look like the one in this game which was my first test:

In this game I am White and even though this is a fuseki designed for Black, I wanted to try it. As far as I can tell and in my best of knowledge, there is no case where having a side stone is detrimental to an approach/joseki. That does not mean that it is good or optimal, however.

I am currently testing the idea and I am planning to start some DGS games against 1 dan players to see how they will deal with it, but I thought I’d begin a discussion here and ask the opinions and ideas of the more experienced players of the forum and whether they know if this has ever been tried, looked into and discarded. And if not, if it is worth checking out.

Thank you for your time. :slight_smile:

Disclaimer: I honestly do not know the answer since I am not much “in the loop” of what Pros or AI play, neither am I deep into Go studing (only studied elementary material during 2016-2017 when I was learning the game). I did check on sensei’s and didn’t find it in Strange Openings, so here I am.


It’s always fun to experiment with stuff, so I hope the experiments go well!

Even if you don’t win as long as you come away with something new it seems good to try!

Random comments:

Example 1: I think the usual idea about say the left side is that white got maybe 30 points with the two corners, while optimistically maybe black can match that, but with some hane connect endgame on the second and first lines, it could be a lot less. On the right side, the stone at 1 maybe isn’t the most useful/obvious how to use, but overall it looks like a big moyo strategy, so you might want to try kill any deep invasions, though the reductions could be just as painful, there’s a lot of openings.

Example 2: 7 and 3 don’t look like the most useful stones, while 1 and 5 are probably decent in terms of nullifying the White influence, which could mean maybe white should choose a mixture or different joseki variations, like don’t fully commit to just one variation like in examples 2 and 3. For example white 12 (or an equivalent) could be at P16 to try keep sente and then enclose another corner or approach/undercut one of the high star point stones.

(they could be things to look out for in the experiments :slight_smile: )


I admit that I am not sure what to do with sente after move 32, in example 1 … possibly play p7 or q7 and start building, would be my best guess.

which could mean maybe white should choose a mixture or different joseki variations, like don’t fully commit to just one variation like in examples 2 and 3.

Quite so, which would make this all the more interesting :slight_smile:


You could even try P5 and hope they connect the peep :slight_smile: See how many of those you can get away with. It might start a fight either, which maybe could work at different levels.

I suppose you could let us know of your progress here, and I guess if anyone else was thinking of experimenting with it they could share here.

Could comment, share variations or review and such :slight_smile:

I’d be happy to play a correspondence game or two if you wanted also. I kind of stopped playing on DGS lately, just too many games too many places, but could play on OGS or DGS etc if you want


The first test against dan players is on:

Unfortunately I got White on the other three challenges, so that’s all I got, for now, on that front.

I’d be happy to play a correspondence game or two if you wanted also.

Sounds great! I’ll send you an invitation to try it out.

Corners are the most efficient place to make eyes and territory, which is why we usually start there. So in the first example white has a decent lead. Of course nothing you can’t lose in later fighting, but white is comfortable. Also white might choose to make an enclosure at some points rather than complete the joseki with one point jump.

In example 2 you are assuming white plays the hane against the 3-3 invasion and takes gote, a white player who doesn’t want you to win is likely to choose a sente variation. But even the result there is good for white as 3 and 7 are badly placed, 5 and 1 are ok.


You might want to ask @_Sofiam about this. She kind of specialized on openings where she doesn’t directly take the corners, and as she’s been playing so many games, she certainly has a lot of experience by now on the pros and cons of different strategies, how often they work out, etc.


On the first glance looks like more grounded version of southern cross.

But the dynamics are very different, aren’t they. Because stones are on the fourth line they’re weaker by default so it’s not about fighting.


With corner joseki you often can ignore other parts of the board and deterministically build same construction again and again in different games. Because only 2 / 4 of sides are influenced by “outside world”.
With side joseki 3 / 4 sides are influenced by “outside world”. Situation where you can ignore other parts of the board becomes much more rare. Long sequence that is same in two different games becomes statistically impossible.
So accumulating knowledge is more problematic if you use side.

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It all looks playable, but even a situation like example 2 seems painful to take, like sure you get corners and mess with their influence but they weren’t always looking to extend from those walls in modern theory and 3 and 7 just become painfully inefficient, whereas none of the white stones bear quite that burden

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The usefulness of sideseki is probably also related to the size of the board.
The smaller the board the less useful sideseki may be.
The larger the board the more useful it probably is.
For 25x25, 27x27, etc. sideseki could come in handy.

New go term

And suddenly a new go term was born: sobaseki (側関).



Is the name sideseki supposed to be a side version of joseki? There’s 2 issues with that. 1. Joseki doesn’t imply corner, side joseki is already a term that makes sense. 2. Joseki are sequences, but this is just putting early stones on side, and then playing normal corner joseki. It’s a kind of fuseki.

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At first I was expecting sekis on the side, but after seeing the moves I thought of it as side(fu)seki.



It makes perfect sense. Side means side and seki means stone(s). Side stones.


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sobaseki (側関).

What does it mean? :slight_smile:

Yes, the Sideseki is a pun on the word Fuseki. I do not speak japanese so I couldn’t create a proper term. Maybe it is the Sobaseki from above?

I try to do this as well, though I rarely know what to do next, so I am unsually the one that is thrown off the correct direction of play. However this is the exact idea that my opponent in DGS is following. This is how the board looks like now and even though the plan was not fulfilled in its entirety, I think that the result is quite ok:

Meanwhile on OGS, the game with @shinuito has progressed quite a lot more:

and it gives an initial test on @Uberdude 's suggestion about White playing joseki sequences that would give sente to White.


I quite like letting them get what they want (if it’s not so great) and then beating them anyway. :smiling_imp:


Sideseki (as a variant of joseki) is a half English, half Japanese newly coined word.
I used Google Translate to translate side (soba) to Japanify this word for 100%: sobaseki.

That’s all.