Sonntag, 13. September 2015

Semeai shortcuts

Something useful for a change, on semeai axioms.

I've been kind of busy recently with the EGF Academy. But I think the time making this post is worth it, as it will collectively save you, my readers, more time in your future games than it took me to make this.
Below I've collected some principles on capturing races.

1.) In the land of the blind, the one-eyed man is king.

 Also known under the less poetic term "me ari me nashi" (have eye don't have eye). It means when someone has an eye vs. a group without eyes, the common liberties belong to the one-eyed group.

By playing the stupid-looking move at 1, Black clearly establishes an advantage in the capturing race of 5 vs. 4 liberties. (Even if White starts playing, White is dead.)

2.) 5, 8, 12, 17

Remember these numbers! A nakade (dead-shape) group with 4 spaces inside has 5 liberties. A nak... actually let me put it in a table:

4 spaces = 5 liberties
5 spaces = 8 liberties
6 spaces = 12 liberties
(7 spaces = 17 liberties, this one is rare and hard to illustrate)

1, 2 and 3 spaces don't have extra liberties other than the visible ones.

These numbers will help you read out semeais faster than ever. Let me explain further though:

Here Black has 8 liberties inside. White has 8 liberties outside.

Playing in the nakade shape counts as taking a liberty. So now Black has 7 liberties inside. White wins by 1 liberty. Feel free to read it out move-by-move if you don't believe me. Then check how much time you could have saved by believing me~

For the slightly more advanced: In a real game, when you count White's territory in this shape, do not forget to subtract 7 (semedori).

Let's look at an example from a real game of mine (I was Black):

I have a nakade 5 shape in the corner. There are 2 stones inside. Then I have the common liberty with White's group. So my group has 8-2+1 = 7 liberties. Using this method, we quickly established my number of liberties.

White's liberties are a simple matter of counting. We can see that White also has 7 liberties, so Black wins by playing first, right?

That's what I thought during the game as well. But looking carefully, White's shape has 2 convoluted cannot-approach-double liberties, so actually White wins by one liberty. That was unfortunate for me.

Fortunately, after capturing Black's group, White's whole-board position is a disaster. Black has sente and controls the whole rest of the board. I also kept the position in the previous diagram (without playing out the semeai), as taking each liberty is an absolute ko-threat. So basically Black can do whatever he wants for the rest of the game, which is what happened. So I won the game after accidentally sacrificing the corner group.
Anyway... :)

3.) In the land of the one-eyed, the bigger-eyed is more king.

In a semeai between 2 groups with 1 eye each, the common liberties belong to the eye with more spaces=bigger eye space.

For White it's actually the same as not having an eye at all. This is the same semeai as in 2.) in spite of White's eye.
(1, 2 and 3 spaces count as the same size of eye.)

4.) Formula for semeai between 2 non-eyed groups

I omitted things like "when both have the same amount of liberties, the one who starts, wins", as I assume you are familiar with that concept. Sometimes, however, there are so many common liberties that you are not sure whether it's a seki or not. There exists a simple formula for that:

Given that: -neither group has an eye (or both groups have the same size of eye),
-it's your turn to play,
-you want to test if you can kill the opponent's group,
you win if

your outside liberties ≥ your opponent's outside liberties + common liberties - 1

Using this formula, we (Black) will try to kill above White's group:

7 ≥ 2 + 6 - 1

This is true, so Black wins by playing first. (If the difference is 1 or more, Black wins anyway.)

To demonstrate it better, White now has one more liberty. If Black tries to kill White:

7 ≥ 3 + 6 - 1

This is false, so Black cannot kill White.

Secondly, can White kill Black?

3 ≥ 7 + 6 - 1

This is obviously extremely false too, so White cannot kill Black either. Therefore the position is a seki.

5.) Semeai that includes ko

-take outside ko first
-take inside ko last

Please try these out by yourselves~

Donnerstag, 10. Mai 2012

No-No Shapes

Warning: This post consists entirely of bad shapes. The persons involved in creating this post are highly trained professionals in this field. Do not try at home.

Througout my Go career I have seen many bad shapes that make me facepalm, over and over again. I have collected samples of common bad shapes and I will clarify their badness using picturesque explanations. My goal will have been achieved if you, dear reader, start facepaming more often than you ever had.

I'm sure you are familiar with

The Empty Triangle

The B2 Bomber

and The Angry Potato

Those are seemingly bad shapes which are, needless to say, indeed bad shapes.

However, I will be writing about stuff which involve hostile stones, like

The Futile Thrust (while giving them cool names)

(followed by a short explanation why it is bad) The exchange of B 1 for W 2 is a bad shape because all it does is improving the enemy's shape. It looks as though White had played two moves in a row.

Which would be these two:

(then I add a picture which shows what the shape looks like to me, which spares me a thousand words of explaining)
To me, the black shape looks rather like

Let's get started!

The Dissected Knight

Sadly, this is a very common shape. Sometimes it is simply the best move to create this shape. However, you need to accept the fact that one of your stones is going to face a harsh destiny of doom.

I see many people voluntarily do this to their poor stones, while being convinced that they are playing on both sides, which is very efficient (not):

Again, this simply looks like Black has played two moves in a row.
Hell, please treat your stones better! They do not deserve getting backstabbed like this by their comrades. A lot of tesuji are about paying a sacrifice to make your opponent play this shape!

Examples of variations of the Dissected Knight:

The Injured Elephant

The Injured and Insulted Elephant

The Galactic Doornail
(There is a joseki that features this one. We can conclude that the Knight is perfectly aware of their Dissection in this case.)

The Dissected Knight shape sort of reminds me of this:
You may argue that this is actually art.

The Masochistic Headbump

Imagine doing this to yourself

The Interstellar Banana

This looks like Black got three moves straight!

Something That Would Traumatise Little Kids

Believe it or not, I've seen this being allowed to happen more than once.

The Vengeance of Alcoholic Ignorance

W 1 is actually a good move... is what I would say if there wasn't a black stone already.

The last shape of this series shall be accompanied by a video.

to be continued

Mittwoch, 7. März 2012

Twisted Logic

I recall a proverb that stated 'There lie bad moves next to tesuji'. However I cannot find it on sensei's collection of Go proverbs so you'll have to trust me it exists. It is not hard to imagine that the spots next to a move which is tesuji are inferior to the tesuji for a tesuji is per definitionem the smartest, coolest, whateverst move in its vicinity.

As some of you readers might know, I've been hospitalized since a while and this was one of the things I spent thoughts on as I have shitloads of time on hand to contemplate every possible flibbertigibbet.

So there I was, playing some on KGS, and this proverb randomly popped into my mind. 'Hmm', I thought, 'this proverb is pretty handy for finding bad moves.'
'How about', I concluded, 'I modify this proverb a little to look for good moves?'
And thus a proverb was rephrased: There lies tesuji next to bad move!

So whenever I am about to play a move I feel weird about, I would apply this and look for the hidden tesuji that may be adjacent to the move I want to play. In theory. In reality I keep forgetting it and play the bad move anyway.

So guys, please try out this fresh method for discovering tesujis in your games and tell me whether it works, thanks a bunch:)

Dienstag, 24. Mai 2011

another blog

while browsing facebook I stumbled upon a (better) blog about the way of go.

you can find lots of other cool stuff there:)

Mittwoch, 18. Mai 2011

Go and Power

Sometimes I feel that people think that the only thing that determines your strenght in Go is how many moves you can read ahead.
I am the living proof that this is not true:) Reading is one of the things I am very bad at. During my progression from 2d to 5d I have improved at many things but reading. Sure reading is important, but it is by far not the only thing that matters.

quote/ Miu from History's Strongest Disciple Kenichi (a manga on martial arts):

Imagine that power equals reading power in Go, I don't have much power, but I do beat strong people occasionally. There must be something else to strenght besides power. (As for me, recently I had a level-up at getting lucky, hehe.)

(Altough I know that it is unwise to reveal details of my Go – my friend wrote about his style in his blog and it was effectively used to scheme a counter strategy against him – I'll just hope that those people who would do that to me don't read this.)

I have relatively strong skills in positional judgement. Another friend pointed out that this enables me to control the flow of a game: when I think that I am ahead, I play along with my opponent, when I don't, I resist. And it might be somewhat true.

Since I am not strong at reading, I try to simplify the game whereever I can. It is the exact opposite of what most people in Dan range do on KGS, I'd like to call that technique randomizing a game. It is somehow scary to play against those people, but in around 50% of their games they just defeat themselves.

If you get the right idea of it, even if you don't have much power, this is what can happen:

Looks cool huh^^

(And this is what can happen to you too if have great power but nothing to back it up.)

I'm sorry that the post didn't turn out as informative as I had planned. I have a non-disclosure agreement with myself and cannot reveal confidential information. (Apart from the manga, all origins from my head. You probably won't find anyone else telling you the same thing. If you do, cool:) )

Donnerstag, 12. Mai 2011

Random sequence

time for another random move
(so, 5k again? If you don't understand the diagrams you can read and try to grasp what I wrote too.)

This is one of the first josekis I learned.

some 20 moves later...

When black plays 26 (the stone is not cut off, it's just your imagination), it would be honte for white to answer at 28. If he decides to tenuki and do nothing else, black can do this trick.

If the ladder works for black, white can only connect to the peep like this. And thus black connects underneath, robbing white off his base and white becomes what you call floating in mid-air.

Where is the ladder?

That is, when white plays kosumi-tsuke with 4 preventing black from connecting underneath. Of course black cuts with 5 and w's sagari with 6 is the tesuji for the corner's capturing race. Since black would lose the semeai if he just takes liberties, he breaks out with 7 and it becomes ugly.
Up to b 13, if the ladder at B works for black, white cannot cut with A. So when black gets to connect at B eventually, the white stones in corner die a natural and peaceful death.
But even if the ladder doesn't work for black, black can settle for an exchange by playing 13 at 11.

Nothing new so far:)

Now we change one stone in the joseki. Black extends with a keima instead of the two-point extension (6 in the very first diagram).

By shifting one stone, if white cuts directly at A, black can play the ladder of 12345 with the help of the triangled stone even if there is the starred white ladder breaker.
Black thinks he is smart, but there is a way for white to outwit black's plan...

Now black should pretty much be swearing again.

Because if black connects to white's attachment, the long awaited ladder has been obliterated.

Dienstag, 10. Mai 2011

the Go player's posture

When I learned under Kobayashi Chizu sensei, she taughe us about the differences between the habits of European Go players and Japanese conventions (sitting at a Goban on a table).

From what I remember of her teachings, this should be a pretty good example:

Since the guy in the picture is right-handed, his bowl is placed at his right and the lid where prisonders are supposed to be put is in both players' field of vision (though for pros it is impolite to count the prisoners in the lid).
Furthermore you can see that the elbows are off the table, the hand is off the lid until the moment he knows where he would play and reaches for one stone from the bowl which he would place on the board in a confident way.
From my experience it is not that strict at the tournaments, but you should avoid rattling with stones or play with them making a lot of noise because it annoys approximately 100% of Go players. Except of course the one Boom! you make when putting the stone on the board.

Alright! Find 3 mistakes in this picture: