Review request 5kyu vs 6kyu (Around)

Hello there,

anybody there to give me an overall review of my game pls:

I guess i lost the game around the unnecssary stupid KO fight by me in the midgame

Anyway thank you a lot!!

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Is that your first game on OGS?
Welcome!

Actually it seems that you were ahead all the time.

White won because you resigned, but the game was still quite even. White was ahead by less than komi.
It could’ve been worth to complete the game and count. A small mistake in endgame can likely cost a few points.

Actually, AI suggests that top right corner wasn’t settled yet, so it was bigger than those five stones in the middle.
Also losing those five stones wasn’t that big because in exchange you would’ve gained two White stones and a couple points.

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Hello!

I have lots of things to say about this game.

You started with the Kobayashi opening.


Figure 1: Kobayashi opening.

This is an opening that was very popular from 1980 to 2016 amongst professionals. It’s been very popular with amateurs too. You can find lots of books and youtube videos about it.

After White 8, here are two possible continuations that were played in professional games:


Figure 2: Variation. This was played in two professional games in 2002. Black builds frameworks on the West side and North side, and White has a weak group in the Northwest corner.


Figure 3: Variation. This was played in a professional game in 2016. Again, Black builds big frameworks on the West side and North side, and White has a weak group in the Northwest corner.

There are a bunch of other professional games that start with the exact same 8 moves. In pretty much all of those games, Black tries to build big frameworks on the West and North sides, while keeping White’s group relatively weak.

In the game, you chose a joseki:


Figure 4: Moves 9-14.

I think that this joseki doesn’t work very well with the two black stones on the West side. One thing to keep in mind when playing this joseki, is that Black’s stones in the Northwest corner are strong and low. By “strong” I mean that your stones are completely alive, and by “low” I mean that your stones are all on the third line. This combination, strong and low, makes the West side very uninteresting. After playing this joseki, the West side doesn’t have much value. Building a framework from low stones is hard. We prefer high stones for that. And playing close to a strength is always bad. Your stones in the Northwest corner are both strong and low, so suddenly no one wants to play on the West side.

We can even do a tewari, an analysis by changing the order of moves. Imagine if the game had gone like this:


Figure 5: Tewari. This is almost like the game, but missing the exchange White 4 - Black 5.

Suppose White hadn’t answered your approach in the Southwest corner, and instead had approached directly your Northwest corner. You play the joseki, which is good in this situation. Then it’s Black’s turn. What do you do? Will you play at A like in the game? I don’t think so. Because your group in the Northwest corner is strong and low, the West side has become very uninteresting. So you don’t want to play at A, and White doesn’t want to pincer at A either. In this situation, Black will either play the double-approach at B, or jump into the corner at C, or maybe approach the Southeast corner at D. Neither Black nor White wants to play on the West side now.

But in the game, it’s too late. You already chose to play on the West side. This is a bit suboptimal; the joseki in the Northwest corner and the Black stones on the West side are not consistent together. You can play the Kobayashi opening, which is good, or you can play this joseki in the Northwest corner, which is good; but playing both together is inconsistent.

Note that a simple way to “fix” the joseki is to play high instead of low:


Figure 6: Variation. Black plays high instead of low, building a framework on the West side.

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At move 15, you played a wide corner extension on the North side.


Figure 7: Move 15.

Looking only at the North half of the board, there are countless professional games where Black played at A, to put pressure on the White group, and countless professional games where Black played at B, to enclose the corner.

Playing at 15 is an in-between move that’s not doing any of those two tasks efficiently. It’s good to try to multitask, but unfortunately it’s often the case in go that an in-between move will be much less efficient.

Playing at A would put a lot of pressure on the White group, because it directly threatens the invasion at the marked point. Playing at B encloses the corner pretty well, preventing a sansan invasion. But playing at 15 does not threaten to invade at the marked point, and does not prevent White from invading at the sansan. In fact, if White invades at the sansan, the stone at 15 is going to feel very suboptimal in the sansan invasion joseki:

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Figure 8: Variation. Sansan invasion joseki.

During the sansan invasion, the marked Black stone allowed Black to play a double-hane at 21, but ends up in a very inefficient shape; Black still needs to add a move at 29 to capture the cutting stone, and the marked Black stone is part of an empty triangle. Compared to the classic sansan invasion of figure 9, Black has lost one move.

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Figure 9: Classic sansan invasion. This is very similar to Figure 8, except Black has spared one move just before White 1.

To summarise: the wide corner enclosure of Black 15 in the game is rarely seen, because it is very inefficient at enclosing the corner.

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Figure 10: Moves 27-35.

In the game, you used move 27 to capture the cutting stone directly, instead of playing the more classic tiger mouth at 29. Fortunately for you, White makes two big mistakes. The first mistake is playing the second-line clamp at 28 instead of cutting directly. White 28 should be at 31, cutting the Black stone. The second mistake is at move 32. White 32 should be at 33. In that case, White would break onto the East side, which would be better for White than staying enclosed into the corner. Thanks to these two mistakes of White, you successfully enclose White in the corner with 33 and 35.

Move 35 is necessary for Black, to protect the cutting point.

However, when a move is necessary like this, it’s time to stop and ask the question: can I get more?

And you can. Move 35 is necessary, you’re going to play it, but it’s also gote. Before you play it, you can play extra moves, which would normally be too small to be sente, but which will be “sente” in this case because White wants you to add the stone at 35. Here is what I’m talking about:

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Figure 11: Variation. Before connecting, Black gets a few extra exchanges.

Sacrifcing the stone at 1 would normally be gote, but if White doesn’t answer, then Black no longer needs to connect at 5 because the three White stones are in atari. So White answers. Then playing atari at 3 on the first line would normally be gote, because the three White stones are very small, but if White doesn’t answer, then Black no longer needs to connect at 5. So White answers.

Thanks to these exchanges, Black has damaged the corner. After the sansan invasion sequence, the corner was in the classic L+2 shape, which is known to be alive. But with the sacrifice of Black 1, the corner is now in a smaller shape, and with the atari at Black 3, the White group is deprived of outside liberties.

In fact, White now needs to immediately add a move, otherwise Black can kill the corner. So, thanks to Black 1 and Black 3, Black can take sente, which is a huge bonus compared to the game.

Here are three cool ways to use sente at this stage:


Figure 12: Variation. Black takes sente and approaches the Southeast corner.


Figure 13: Variation. Black takes sente, sweeps the life-base of White’s group, then approaches the Southeast corner.


Figure 14: Variation. Black takes sente, and builds a moyo on the East side.

But actually, thinking about it… If White absolutely needs to add move 6 to stay alive… Can Black omit move 5 and kill White directly? It’s more complicated, and probably unnecessary, but you can. The white cutstone at P16 is captured in a ladder, so Black is not too afraid of the cut.


Figure 15: Variation. Black tries to kill the corner.

When White plays at A, it’s going to start a ko for the life of the White corner. White has a lot of ko threats, but so does Black, and White now has an additional weak group at stones 8 and 10. These two stones are probably going to die. If White absolutely tries to save them, while also trying to win the ko, then the White group in the Northwest is going to become very very weak and Black is going to have a lot of fun.

To summarise: when you need to add a move like Black 35 in the game, try to gain something extra by playing sente moves that wouldn’t be sente otherwise. In this case, the sacrifice at 1 and the atari at 3 would be bad moves if you played them after connecting at 35, but are really good moves if you play them before connecting.

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Continuing from move 36.


Figure 16: Moves 36-43.

With moves 37 and 39, you begin a nice sequence of flattening White and building a moyo on the East side. White makes a mistake at move 38, playing on the second line. White should have played at 40 directly. You benefit from this mistake immediately, by playing at 39 and forcing move 40.

However, you then change ideas, and play on the third line at move 41. Move 41 is bad for at least three reasons.

First reason. Do not play close to a strength. Move 41 is close to your strength. There is an important principle in go, which is: never play close to a strength. That means never play close to your own strength, and never play close to your opponent’s strength. A strength is a group which is completely alive. Your black group in the Northeast corner is completely alive. With the tiger mouth that you played at move 35, and the captured white stone (which you can choose to take with a ladder or with a net if it tries to escape), plus the two empty triangles, your black group has at least four eyes, if not more. That’s enough eyes to be alive and strong. Move 41 is way too close to that strength.

Second reason. Shape. By allowing white to play at 42, you’re giving white a tiger’s mouth, which is a great shape for White, and a hane at the head of two stones, which is a horrible shape for Black. Now, your two black stones 37 and 39 are in a very bad position. They’re weak, they lack liberties, they’re almost surrounded by the White stones. It looks like White could almost capture them with a single move at R7. This is a terrible development. Two moves ago I was praising the way you were building a moyo and erasing white’s influence. Now it’s White who is building a moyo on the south side, and Black who has a horrible shape. Shape shape shape. After White played move 40, the intersection 42 is blinking like a flashing light on the goban. You should play it immediately. Black 41 should be at 42 instead.

Third reason. Playing influence. This is actually the same reason as the first reason. You have a very strong group in the Northeast corner. It’s not just a wall. It’s a strength. Do not use that strength to build a super-small third line territory. That’s a huge waste. Use that strength to build a large moyo. Note that in the game, your territory on the East side is not really existent anyway, because White has a second-line stone at 38, so your territory is wide open. A territory which is super-small, on the third line, and wide open, that cannot be good. Not to mention that if White played at R7, your two black stones would probably die anyway, so this is all for nothing. In the game, you start by making this super-small territory on the East side, offering White a huge moyo in the South side in exchange. And then you invade White’s moyo with 43. It would be much easier to do the exact opposite: build a huge moyo for yourself. White is the one who will have to invade. You have a big strength in the Northeast, and White already has one weak group in the Northwest. Be ambitious. Maybe something like this:


Figure 17: Variation. Black plays as far as possible from its Northeast strength.

Continuing with the game, things become incredibly good for you.


Figure 18: Moves 44-54.

White’s moves are very, very slow. White 44, white 46, white 48 are all very small and very slow moves that don’t accomplish a lot. White 48 in particular, is beating a dead horse; Black is happy to sacrifice the two Black stones which were already in a terrible shape and stuck against White’s strength. Also note that White 54 would be slightly better at A instead. Playing at A instead of 54 would make it easier for White to build eyespace, and it would also reduce Black’s corner. After White 54, KataGo gives 99% winrate for Black.


Figure 19: Moves 55-75.

Black further consolidates their lead. Move 55 strengthens Black’s only weak group. The exchange White 55 - Black 57 strengthens Black’s group, without accomplishing much for White. White’s invasion at 58 is probably a good idea, but the cut at 60 is unnecessary - White could have played at 66 directly to make a life-base without giving that much to Black: see Figure 20. White 74 is a big mistake: it does not protect the marked cutting point. White should have played a tiger’s mouth at A instead. Black 75 outlines a territory in the centre, and at the same time helps connect Black’s weak group, which is very good.


Figure 20: Variation. White makes a life-base without sacrificing a stone, giving fewer points to Black.

It’s hard to criticise Black’s next moves, because Black is already so much ahead that there isn’t much interesting to say. Playing it safe is good.

KataGo notes that with White’s attack at move 76, White is creating a third weak White group. Because White has three weak groups, Black can afford to be much more violent and ambitious:


Figure 21: Variation. Black exploits White’s three weak groups to claim a large area in the centre.

But playing it safe is good. The most important thing is not to let your group in the South die.

Black’s move 91 is a mistake and should better be at 92 instead. It would create a better shape for Black, make it easier for Black to connect their stones, and make it much harder for White to connect their stones:


Figure 22: Variation. Black makes a better shape at 1 instead of move 91. The two White groups are separated, and Black can attack the two groups at the same time.

Continuing.

Black move 115 is a big mistake. You should have played at 117 directly. Be very glad that White failed to punish the mistake, by playing at 117 themselves:


Figure 23: Variation. White immediately punishes Black’s mistake and captures 4 black stones.

Black move 137 is a weird mistake, playing on the first line directly. You should have played the simple shape move instead:


Figure 24: Variation. Black plays a simple move that gives a good shape to Black, gains territory on the third line, adds liberties to the Black stone, etc. There is no reason not to play this.

Your first-line move at 137 gives an awkward shape to Black. In fact, White could have punished directly and captured your stones with a clamp:


Figure 25: Variation. White punishes Black’s awkward shape by immediately capturing the Black stones.

Even if you didn’t read the sequence of Figure 25 precisely, you should have smelled the bad shape. Even if White plays a simple tiger’s mouth, it would already be much better for White than the variation of Figure 24, where Black plays the simple good shape:


Figure 26: Variation. White doesn’t notice that they can capture the Black stones, but still gets a much better result than in Figure 24.

After the variation of Figure 26, Black must finish gote and add a protection move, otherwise there is still a big weakness in the Black shape:


Figure 27: Continuation after Figure 26. If Black plays a tenuki, then White captures the Black cutstone.

All of this just because you were greedy and played the first-line small endgame at move 137 instead of the simple and solid shape move of Figure 24. This kind of shape-move should look like a blinking light on the go board. You must see it and you must play it. This is almost the same shape as move 42 in the game, Figure 16, or move 1 in the variation, Figure 17. These are very important shape moves that you must learn to recognise.

At move 149 you capture a White stone. There is absolutely no reason not to push once before capturing:


Figure 28: Variation. Black pushes once at 1 to reduce White’s territory and damage White’s shape, before coming back to the capture at 3.

There is at least a 2-point difference between the variation of Figure 28, and the game, where you captured at 3 directly without pushing at 1. There is absolutely no reason not to play this variation.

The exchange Black 169 - White 170 is a big loss for Black. If you want to take sente, then take sente directly - do not place a Black stone in atari first!

Black 181, a move starting a ko, is also a big loss for Black. For two reasons. The first reason is that it immediately follows White 180, which is a sente move that you forgot to answer!


Figure 29: Moves 180-181. White plays an atari, Black forgots to answer, and Black starts an imaginary ko.

The second reason why Black 181 is a mistake is because it simply does not work. The ko is only in your head. White can easily capture the Black stones without a ko:


Figure 30: Variation. This is not a ko.

At move 183, you play a tricky ko threat and White makes a big mistake when answering it with 184. You should not take back the ko; you should immediately punish White’s mistake.

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Figure 30: Black immediately punishes White’s mistake.

In the game, you take back the ko, and White’s next ko threat erases the weakness in White’s territory, making White’s previous mistake disappear:

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Figure 31: After White’s next ko threat, the weakness in White’s shape disappears.

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I added a review to the game:

One thing worth noting is that it isn’t just losing five stones: black loses five stones, and also loses a capture on six white stones (assuming black plays everything correctly) and most of the territory on the right hand side of the board. There is a bit of a pick up for winning the ko, but black is going to come out -10 or more compared to giving up on the ko fight and defending solidly.

My bad that I didn’t browse the whole game.
I just evaluated the last two moves and the final situation.

That was because I was aiming at OP evaluation of the board. The OP says:

What I wanted to stress is that the game was far from lost.
I didn’t look at why those five stones were captured. I didn’t even notice that there was a ko fight right before that capture.
I just saw that the difference in score through all the game was less than 15 points and that the game ended when white captured five stones and black resigned.
I thought it was a sort of rage quit because of that capture and wanted to stress that, despite losing those stones, the game was still pretty even.

But you’re right.
Losing those stones was also about letting live most of white stones that previously were captured or threats inside black territory.
Despite that, AI evaluates the connecting move at D13 being just -8.4 points.
After connecting and losing the five stones, black drops from +10.7 to +2.3 because there’s more somewhere else.
The following move at M10 is worth 6.4 more points thrown away. Yet the overall situation is just W +4.1, not so bad for my level of play.

We don’t know klept_GO_maniac’s rank. He played just one ranked game on OGS and obviously he isn’t a complete beginner. I can’t evaluete his strenght and he could even be stronger than me. But apparently he doesn’t know how to read the AI chart that is displayed after the game is finished.
That was my focus and the reason why I overlooked the rest of the game.

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