Life In 19x19

Posted: **Sun Mar 06, 2016 5:29 am**

I've been watching a lot of Dwyrin's lectures on youtube lately, and I noticed that he seems to favor Q-17 as black's first move instead of R-16 and I can't seem to find any study materials for why people would like this move best.

My best DDK guess would be that the direction of play is better, because if white plays D-16 it would be point at your stone if your played R-16? It could be better for playing Q-4 as black's second move. It also looks like like encloser at Q-17 and R-15 with a stone at Q-4 instead of R-16 and P-17 would skew everything once space closer to Q-4 making everything a little tighter??

Anyway, I was wondering if anyone had any links to some study material so I can understand the pros and cons of Q-17 vs R-16?

Posted: **Sun Mar 06, 2016 6:20 am**

For the FIRST move of the game, you need to understand the symmetries of the go board. All moves that would be the same under reflection or rotation are equivalent, not really different moves.

The relationship between Q17 and R16 is a reflection followed by a rotation. They are NOT (in effect) different first moves.

As an exercise for yourself, what are all the other points that would be equivalent first moves? (in effect, the same as Q17)

Posted: **Sun Mar 06, 2016 6:32 am**

R16 is the "traditional" way of play.

In historical Japan, the players wore kimono with long sleeves.

It was considered to be "polite" to allow the opponent attacking this corner stone (e.g. with a move at P17, or P16) WITHOUT any need to move OVER the initially played stone.

Posted: **Sun Mar 06, 2016 6:37 am**

Mike Novack wrote:For the FIRST move of the game, you need to understand the symmetries of the go board. All moves that would be the same under reflection or rotation are equivalent, not really different moves.

The relationship between Q17 and R16 is a reflection followed by a rotation. They are NOT (in effect) different first moves.

As an exercise for yourself, what are all the other points that would be equivalent first moves? (in effect, the same as Q17)

They are all the same until they are responded to. I can't get my SGF to load so I'll have to type this out. Imagine two different boards each with two stones. Board A has a black stone at Q-17 and a white stone at D-16. Board B has the same white stone at D-16 but a black stone at R-16. These two boards do not look the same to me.

EDIT: I guess I should expand on this a little further. Let's say the game has gone a few more moves on both of our imaginary boards. White played the D-4 and black played the Q-4 on both boards. This makes it turn 5 and blacks turn. On board A (Q-17) he could play R-11 and it would be Small Chinese (although upside down.) I'm not crazy right? These positions are different! I feel like I'm going a little crazy with the lack of information I'm finding on this topic.

Posted: **Sun Mar 06, 2016 7:15 am**

I’ll do my best to explain it in english, though it’s a bit difficult

.

The 10-10 point (tengen) is the middle and can therefore be used as a mirrorpoint. Draw two lines from corner to corner, when you fold the board along those lines a position from one side would be mirrored on the other side.
You can draw this lines from edge to edgo too, going through tengen. You get a “normal”, upright cross like this: +. You fold it along those lines, you have the same mirror-effect. (of course not exactly the same

)
And you can rotate the board around tengen.

I hope this helps you to wrap your head around it.

You can have a look here https://en.wikipedia.org/wiki/Reflection_%28mathematics%29 too, but that’s very mathematical.

Posted: **Sun Mar 06, 2016 1:11 pm**

Faro wrote:
EDIT: I guess I should expand on this a little further. Let's say the game has gone a few more moves on both of our imaginary boards. White played the D-4 and black played the Q-4 on both boards.......

Stop. You asked about the FIRST move, what was different between those two choices FOR FIRST MOVE. I said no difference based on symmetry. Except for tengen (the center point) each FIRST move is one of a set of either four or eight equivalent moves. Tengen is the only unique first move possible.

After white has moved, might no longer be symmetrical.

Posted: **Sun Mar 06, 2016 1:17 pm**

Mike Novack wrote:
Faro wrote:
EDIT: I guess I should expand on this a little further. Let's say the game has gone a few more moves on both of our imaginary boards. White played the D-4 and black played the Q-4 on both boards.......

Stop. You asked about the FIRST move, what was different between those two choices FOR FIRST MOVE. I said no difference based on symmetry. Except for tengen (the center point) each FIRST move is one of a set of either four or eight equivalent moves. Tengen is the only unique first move possible.

After white has moved, might no longer be symmetrical.

I'm sorry, I I made a poor job of explaining what I meant exactly. My question was as a first move with the knowledge that you would be making follow up moves, and an overall fuseki. I was asking if playing one or the other, depending on how white responded, had an effect on opening. Basically could one lead to opening or situations that would be favorable over other outcomes.

Posted: **Sun Mar 06, 2016 1:38 pm**

The first move cant matter. You should convince yourself!

Posted: **Sun Mar 06, 2016 2:03 pm**

Faro wrote:
Mike Novack wrote:
Faro wrote:
EDIT: I guess I should expand on this a little further. Let's say the game has gone a few more moves on both of our imaginary boards. White played the D-4 and black played the Q-4 on both boards.......

Stop. You asked about the FIRST move, what was different between those two choices FOR FIRST MOVE. I said no difference based on symmetry. Except for tengen (the center point) each FIRST move is one of a set of either four or eight equivalent moves. Tengen is the only unique first move possible.

After white has moved, might no longer be symmetrical.

I'm sorry, I I made a poor job of explaining what I meant exactly. My question was as a first move with the knowledge that you would be making follow up moves, and an overall fuseki. I was asking if playing one or the other, depending on how white responded, had an effect on opening. Basically could one lead to opening or situations that would be favorable over other outcomes.

Assume you had a glass board so you could see through it, and you played a move on it. Would sitting on a different edge or looking at it from beneath (or both) lead to a different position? Even after several moves have been played?

Posted: **Sun Mar 06, 2016 2:13 pm**

hopefully, diagrams can go a long way in helping to explain things...

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . 1 . . . | $$ | . . . , . . . . . , . . . . . , 1 . . | | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+ +---------------------------------------+[/go]

These two moves (above) are symmetrically identical. No difference. Rotate and flip the board over to see.

But white can break the symmetry with its next move, and black has absolutely no control over where white plays next. Black's first move can not influence where white chooses to play next.

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . 1 . . . | $$ | . . . 2 . . . . . , . . . . . , 1 . . | | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . 2 . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+ +---------------------------------------+[/go]

Here (above), white's second move is the same (in relation to black's first move)

But below, white breaks the symmetry with its 2nd move -- notice that black's moves are symmetrically the same as above. But its white that chooses to play differently this time.

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 1 . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . , 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | | . . . , . . . . . , . . . . . 2 . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+ +---------------------------------------+[/go]

Posted: **Sun Mar 06, 2016 2:36 pm**

The point might be that many white players will play the top left corner as their 2nd move regardless of which 3-4 black plays in the top right, in which case the resulting positions are very different in terms of how white's approach is related to the top left corner.

Posted: **Sun Mar 06, 2016 4:05 pm**

Uberdude wrote:The point might be that many white players will play the top left corner as their 2nd move regardless of which 3-4 black plays in the top right, in which case the resulting positions are very different in terms of how white's approach is related to the top left corner.

YES! That's it exactly. If you can be reasonably sure that white will respond in the top left, does one 3-4 point have a benefit over another?

Posted: **Sun Mar 06, 2016 4:54 pm**

Faro wrote:YES! That's it exactly. If you can be reasonably sure that white will respond in the top left, does one 3-4 point have a benefit over another?

Uh ..... why would you suppose white would be more likely to respond in the top left rather than the bottom right?

Try looking at what you said in reverse. You seem understand that the positions would be different if white responded in the upper left. Presumably white would prefer one of those to the other, yes? Well in that case, white would have chosen to have responded in the lower right.

Posted: **Mon Mar 07, 2016 1:34 am**

Mike Novack wrote:
Faro wrote:YES! That's it exactly. If you can be reasonably sure that white will respond in the top left, does one 3-4 point have a benefit over another?

Uh ..... why would you suppose white would be more likely to respond in the top left rather than the bottom right?

Experimental evidence.

Mike Novack wrote:Try looking at what you said in reverse. You seem understand that the positions would be different if white responded in the upper left. Presumably white would prefer one of those to the other, yes? Well in that case, white would have chosen to have responded in the lower right.

"could", not "would". Humans are creatures of habit. Many players play the first 2 moves without really considering the opponent's corner stones.

Life In 19x19

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