Strategy Spotlight

15 May 2010 No Comments

Strategy Spotlight: The 4-4 Kosumi Contact

Ever since I got back from the student OZA in Japan, I’ve been loaded with work that I blissfully missed. After a good month or two however, I should be again in position to return to writing strategy spotlights!

Today, we look at an unusual variation of the standard 4-4 approach.


Diagram 1.

Everything up to 4 is perhaps one of the most ubiquitous Joseki’s you’ll find. White, however, decides to spice things up with kosumi of 5. What is the purpose of this move and how how should black reply?


Diagram 2.

Black’s first instinct might be to play a hane at 1, following with the Atari at 3. While this might give some instantaneous gratification, black is left with no ideal follow-up. One possible method if to play the sacrifice tactic of 5. After white 10, black blocks at a, follow by white b. White has gained magnificent thickness on the top, while black’s influence is hampered by the peep at c. This is clearly unsatisfactory.


Diagram 3.

The proper response is the unlikely empty triangle at 1. White plays actively with the forcing moves of 2 and 4, and finally fixes his shape with 6. While black’s moves feel rather submissive, he is usually satisfied that the marked white stone looks out of place.
White on the other hand, has achieved his strategic objective. His group on top is much stronger than the standard joseki and can much more readily create a moyo up top. The cost, of course, was to leave black’s corner totally without weakness.

White thus chooses this joseki when the potential on the top side is of great importance. For example, when white already has significant influence on the top left, or when black is sufficiently strong on the left side such that this variation leaves him overconcentrated.
Black, however, may choose to challenge white’s plan.


Diagram 4.

He has the option of playing 3 in diagram 3 at 1 in diagram 4, inviting a massive fight. The moves up to white 10 are one natural continuation. Locally, the fight is not necessarily good for white, but white should have only played the marked stone at the start if he had supporting influence on the top left. Assuming that’s the case, both black and white will have weak groups to contend with. It’ll be a fighting game!

The above game highlights a pro match where the strategy was employed by Korean 9p Ch’oe Ch’eol-han at move #37. As black, Ch’oe has built up significant influence on both the bottom and top right and felt that the standard joseki on the bottom left would no longer be satisfactory. White chose to resist, resulting in a massive fight. If you like this style, give it a try!

by Mile Gu in Strategy Spotlight

26 Feb 2010 1 Comment

Strategy Spotlight: Deep Invasion of Oversized Moyos

This week, we take a break from variations on corner josekis to investigate something that’s close to the mid-game. How does one make a deep invasion into a massive half board moyo?


Diagram 1

Consider for example, a San-rei Game, where black intends to build massive region on the top of the board. For most of us, such large moyos are scary objects. The calmest way, would of course, to recognise than one had already made significant profit:


Diagram 2

Something like diagram too might occur. Such a reduction would have little risk for white, and the result may even be considered rather advantageous. Black’s territory on top is certainly impressive, but white has gained a good amount of territory on both sides. Later, White can cut away black’s corner with a, and exploit the weakness at b for further invasion. However, for some players, the prospect of giving the opponent so much territory is, at the very least, psychologically bothersome.

So, what are the options for deep invasion?


Diagram 3.

The attach at 1 looks like a natural position. After black hanes, the hane at 3 is the natural move to seek survival….


Diagram 4.

However, with so much strength on outside, there’s good chance that black can kill white completely. White, of course, has other options, such as playing white 3 and black 4 in Diagram 3 and hoping to use the corner aji. However, white’s chance of living is never that great.


Diagram 5.

A better approach is to consider a capping play at 1. Obviously if black submits by playing at a or b, then white plays c and the resulting exchange gives him a much superior position to diagram 2. Black therefore, must cap at 2. White now returns to playing 3. When black hane’s, white crosscuts at 5. With the support of 1, the situation is significantly different.


Diagram 6.

For example, if black extends with 1. White exploits the circled stone to the max with the sequence 2-8. Whites resulting survival, of course, remains unguaranteed. However, the groups of stones is now rather resilient, with possibility to make eye space at A, B and C. Killing the group will be difficult.


Diagram 7.

Should black extend the other stone, white continues with 2-8. Once again, whites group becomes rather resilient to attack. Black may attempt a cap at a, but white has the ability to attach at b, and a good amount of eye space as well.

That’s not to say, of course, that white is completely out of danger. However, should white live, Black’s large sacrifice both corners would have conceived few rewards. If you’re a fun of a fighting game, you may like to try such an approach against an oversized moyo.

by Mile Gu in Strategy Spotlight

19 Feb 2010 2 Comments

Strategy Spotlight: Punishing the Kobayashi 1 Space Approach

This week, we explore a extremely punishing sequence that’s available  to black when white plays a high approach to black’s 3-4, when it has support in the region of the triangle stone. This sort of pattern happens quite frequently, in, for example, the Kobayashi Fuseki.


Diagram 1.

Typical responses to the high approach involve close pincers at a, or 6, reasoning that this forces white to jump out towards the triangle stone, and any running fights would be in black’s favour. Recentally, however, black has been given an additional option.

Instead, black feints submission with 2 and 4. Just as white expects black to complete the standard joseki with b, he makes a punishing pincer at black 6. White is now much heavier than the case where black pincers directly.


Diagram 2.

White’s first instinct, of course, is to punish black’s defect shape in the corner with 1, to which black calmly responds at 2. If white pulls back at 3, black happily connects at 4. White is left with a heavy group, that must either run out eyeless, or concede further thickness to black with the sequence 6 to 10. This is clearly unsatisfactory.


Diagram 3.

Therefore, white boldly cuts black with 1, a necessary move, regardless of result. The corner descends into chaos. Black triangle, however, ends up in a perfect position. White is now split into two groups, and will find it extremely difficult to save both.


Diagram 4.

If, white for example, chooses to help the four stones on the left, black effortless walls in the triangle stones on top. Even if these stones somehow survive, the thickness that would gave black is unthinkable.


Diagram 5.

Therefore, white 1 in Diagram 2 is overplay. The best white can hope for is the settled with the sequence 1-8. Although he managed to get sente, black’s left side has been solidified, and blacks top right now has a lot of potential. This does not look good for white at all. So…. where did white go wrong?


Diagram 6.

To answer, we’ll have to backtrack all the way to the initial approach. If black is strong on the left, white best stay away. 1 is a much better idea, to which black responds with a or b.


Diagram 7.

The feint plus pincer, however, is a good sequence to keep in mind. Even in cases where Black has no stone at a, the option is possible whenever black has significant strength in the bottom left and top right. Diagram 7 outlines one possible sequence of moves. The result will now depend entirely on surrounding conditions. Play this is you like seeing blood, though it could be your own!

by Mile Gu in Strategy Spotlight Tags:

05 Feb 2010 2 Comments

Strategy Spotlight: Territory focused Chinese Fuseki

This week, we consider an unconventional defence against an enemy approach to a common pattern that arises from the Chinese fuseki.


Diagram 1.

When white makes the corner approach to reduce Black’s potential, the orthodox reply is at Black 2. What follows is a standard pattern that many of you would have mostly likely encountered, especially if you’re a fan of the Chinese fuseki.

At any rate, Black is usually satisfied with this result, white 7 looks reasonably cramped, and black has increased the potential territory on both the left side and the top right by playing either a or b. In either case, white generally needs to respond at c. Meanwhile, white cannot complain too much, since he must of had three free moves elsewhere on the board.


Diagram 2.

There are times, however, when Black might feel his behind in territory. Or perhaps, the moyos are just not that important. In these situations, Black can choose the unconventional move at 2.


Diagram 3.

White might first look at black in puzzlement. Surely he has made a mistake? White’s most obvious response is at 1, and if things proceed as in diagram 3, black cannot possibly be satisfied. The circled stone looks flat on the third line ineffective. Meanwhile, white’s shape is solid, and it looks like white has successfully neutralised black’s moyo. What could black be thinking with 2?


Diagram 4.

Diagram 3, in fact, is just wishful thinking on white’s part. Black 1 starts the small avalanche Joseki, making maximum use of his extra circled stone. After white 6, Black 7 is essential. Playing this move at a is also joseki, but a total mistake in this context.


Diagram 5.

When white continues the joseki with the cut at 2, black’s circled stone looks perfectly positioned. If it were not there, black would be forced to play 5 at 7, and thus allow white to seal off the top in sente. With the stone, however, is it white 2 and 4 that is under pressure. By Black 7, white has two unsettled groups against black’s one. What’s more, black has taken a solid corner. The ensuring fight will be in black’s favour, and white has been completely tricked. Note that if white a, black can counter with b. Black 7 can also be played at c, but white d is sente.


Diagram 6.

So what is white’s best response? To answer that, we’ll need to rewind to the beginning. Despite first intuition, white’s only choice is to hane at 3, and play lightly at 5. With Black 6, black has completed his goal of securing a significantly larger corner than diagram 1. The result, however, is not one-sided. White’s light group is difficult to attack. Later, white can protect his cur with the 7/8 exchange, and then press down with 9.

If the top right is unimportant, black 2 is well worth a shot. In all likelihood, the enemy will walk right into a small avalanche, and end up fighting for his life.

by Mile Gu in Strategy Spotlight

29 Jan 2010 5 Comments

Strategy Spotlight: Breaking out of San-ren-sei

This week, we’ll spotlight a violent variation of the standard 1 space pincer that happens so often in games involving the san-ren-sei.


Diagram 1.

When white makes the standard corner approach against san-rei-sei, the one-space pincer at black 3 is a very common response. Black aims to maximise the effectiveness of black 1, and create an impressive moyo on the top. White 8 is more commonly played at a, followed by black b, this seems to submit to black’s plan of sealing white inside. Mind you, this doesn’t mean whites at a is disadvantageous, the result is considered even.  In this diagram, white 8 suggests that she actively wishes to spite black’s game plan from the very start.


Diagram 2.

The standard continuation (Diagram 2) of the joseki, however, still results in white sealed within the corner. After white 10, black either protects his cut directly at a, or first ataries at b. White has gained a few extra points compared to Diagram 1, but black’s influence seems even more impressive. For this reason, most players would prefer the more standard variation where the marked white stone was is played at 5.


Diagram 3.

Recently, however, pros have experimented with a highly aggressive variation. After Black hane’s, white plays an empty triangle at 2. Is this an overplay? It certainly looks like it! Black 3 is clearly a must, playing at a and allowing white b is clearly unbearable. White looks to be in a difficult position… if not for the severe clamp at 4. The fight is on.


Diagram 4.

If black submits at 1, the remaining moves up to white 8 are almost forced. White settles his center group with 8, and black is left with nothing to attack. This thick white group in the middle will make it difficult for black to form any large scale moyo, and black feels like he has been tricked.


Diagram 5

Black can alternatively play the severe moves and 1 and 3. After a sequence of forced moves, white finished with the terrifying cut at 10. The fight becomes frantic, but black looks to have the harder end of the stick.


Diagram 6

So what is black’s best response? That’s still an open question. Diagram 5, for example, shows one possible variation that occurred between pros. One thing is for sure though, white should not try this move is she’s not willing to put up a huge fight.

So, if you don’t like facing giant moyos, and prefer a game filled with fighting, you can give this a go. Again, this tip was possible due to the extremely helpful advice of Kang ZhanBin 6p.

by Mile Gu in Strategy Spotlight Tags: ,

17 Jan 2010 4 Comments

Strategy Spotlight: The Large Knight Response

First of all introductions. My name is ‘Mile Gu’, a go player from Auckland, New Zealand who studied at the University of Queensland. Given that I’ll be representing Oceania in the coming Student OZA competition, I volunteered with the encouragement of the Brisbane go club to contribute some humble tips to the Australian Go Journal, and give an insider account on the future competition. My accounts on KGS are Syptryn and Zyptryn (The latter when I’m too sleepy to play well). If you have a question that a 4 Dan could potentially answer (or at least make an educated guess), feel free to drop me a message if you spot me online!

To begin with, I’ll be presenting a semi-regular ‘Strategy Spotlight’. The goal of these columns will be to highly some unconventional or trick plays, so you you can either employ them, or at least know how to handle it if someone tries to pull it on you. They’ll be tailored for a range of skill levels, but probably most useful for low dan and high kyu players.

The Large Knight Reponse to 4-4 Attach:


Diagram 1. The Large Knight Move.

When white attaches with 1, black plays 2 instead of the more usual a or b. This isn’t trick play, but is a somewhat special strategy.


Diagram 2.

If black continues using the standard sequence of Diagram 2, she can’t help but feel unsatisfied. White circle is in a better position than a. If this was blacks’s guaranteed response, than there will be no reason for white to ever play a. So how should black punish white? The trick is observe that black circle leaves the corner far more open. black should usually jump in the corner as in Diagram 3. Diagram 3 and 4 shows one standard continuation.


Diagram 3.


Diagram 4.

The result is considered fairly even, so the Large Knight move is fully playable in certain situations. For example, when white has a strong position at the top, so that the two isolated black stones can be severely attacked. Feel free to try it in your next game!

by Mile Gu in Analysis, Strategy Spotlight Tags: