Life In 19x19

n18 seems bigger to me than L5...

Let's try to quantify how big l5 is then. Locally the game went as follows,

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 2 . . . . . . |
$$ | . X O O . O . . . . O O . X . X . . . |
$$ | . . X O . . . . O O X X X . X , X X . |
$$ | . . O . . . . . O X X . . X . X O . . |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O . X . X O X . . |
$$ | . X X O O O O . 7 . 9 8 . X O . O . . |
$$ | . O X O . O X O 6 5 1 . X O O O O . . |
$$ | . X O O O X X X X , . 3 4 X X O . . . |
$$ | X . X X O O X . . . . . . . . X O . . |
$$ | . X . . X X . X . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ ---------------------------------------[/go]

And then after black had got s3 (so lower right super alive) he played to increase territory on left and damage right in sente, which did actually surprise me as I thought m2/m3 was likely best local yose for him, but lets count this instead of the ambiguous position above. So here white spent 2 moves to get 2 points at k6 and reduced black to the triangled territory.

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[go]$$Bcm10
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . X . . . . . . |
$$ | . X O O . O . . . . O O . X . X . . . |
$$ | . . X O . . . . O O X X X . X , X X . |
$$ | . . O . . . . . O X X . . X . X O . . |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O . X . X O X . . |
$$ | . X X O O O O . O . O X . X O . O . . |
$$ | . O X O . O X O X O O . X O O O O . . |
$$ | . X O O O X X X X , . O X X X O . . . |
$$ | X . X X O O X . T . 1 2 6 . . X O B . |
$$ | . X . . X X . X T T 5 3 4 . X T X . . |
$$ | . . . . . . . . T T T . . . . X . . . |
$$ ---------------------------------------[/go]

Compared to black first at l6: the same triangles are marked and squares are the extra black territory. There's 20 of them. So that's swing of 22 for 3 moves difference or 7 1/3 points per move. (I ignore slight change at h5 because when black defends white gains by saving that in sente, but black gains by getting h8 peep to help with centre thinness.)

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . a . . . . . . |
$$ | . X O O . O . . . . O O . X . X . . . |
$$ | . . X O . . . . O O X X X . X , X X . |
$$ | . . O . . . . . O X X . . X . X O . . |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O 2 X . X O X . . |
$$ | . X X O O O O . . X 1 3 . X O . O . . |
$$ | . O X O . O X O 4 5 S S X O O O O . . |
$$ | . X O O O X X X X S S S S X X O . . . |
$$ | X . X X O O X . T S S S S S S X O . . |
$$ | . X . . X X . X T T S S S S X T X . . |
$$ | . . . . . . . . T T T S S S S X . . . |
$$ ---------------------------------------[/go]

Now for the top, if black spends 1 gote and gets sente monkey jump:

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[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . 6 3 5 9 . . . . . . . |
$$ | . . . . . . . . 0 4 8 7 1 B . . . . . |
$$ | . X O O . O . . . . O O W X . X . . . |
$$ | . . X O . . . . O O X X X . X , X X . |
$$ | . . O . . . . . O X X . . X . X O . . |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O . X . X O X . . |
$$ | . X X O O O O . . X . . . X O . O . . |
$$ | . O X O . O X O . . . . X O O O O . . |
$$ | . X O O O X X X X , . . . X X O . . . |
$$ | X . X X O O X . . . . . . . . X O . . |
$$ | . X . . X X . X . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ ---------------------------------------[/go]

If white spends 2 gotes then I don't know how to count top right for black, but white has gained 8 squares compared to before.

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . S S S S S . . 3 . . . |
$$ | . . . . . . . . S S S . 1 . . . . . . |
$$ | . X O O . O . . . . O O . X . X . . . |
$$ | . . X O . . . . O O X X X . X , X X . |
$$ | . . O . . . . . O X X . . X . X O . . |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O . X . X O X . . |
$$ | . X X O O O O . . X . . . X O . O . . |
$$ | . O X O . O X O . . . . X O O O O . . |
$$ | . X O O O X X X X , . . . X X O . . . |
$$ | X . X X O O X . . . . . . . . X O . . |
$$ | . X . . X X . X . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ ---------------------------------------[/go]

If black gote, he has 8 points (squares) in corner beyond triangles.

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . 5 7 3 4 S S |
$$ | . . . . . . . . . . . . 1 . . 6 8 S S |
$$ | . X O O . O . . . . O O . X . X S S S |
$$ | . . X O . . . . O O X X X . X , X X S |
$$ | . . O . . . . . O X X . . X . X O T T |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O . X . X O X . . |
$$ | . X X O O O O . . X . . . X O . O . . |
$$ | . O X O . O X O . . . . X O O O O . . |
$$ | . X O O O X X X X , . . . X X O . . . |
$$ | X . X X O O X . . . . . . . . X O . . |
$$ | . X . . X X . X . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ ---------------------------------------[/go]

If white gote, then white is creating followup at a which actually makes ~4 points in the corner, and black's move there only makes ~3, so let's say current value is 2 for white, 1.5 for black so net -0.5 for black which I will round to 0. So if black gote was 8 and white gote was 0 then current value is black expects 4 points.

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . 3 . . . |
$$ | . . . . . . . . . . . . 1 . . . 5 . . |
$$ | . X O O . O . . . . O O . X . X . a . |
$$ | . . X O . . . . O O X X X . X , X X . |
$$ | . . O . . . . . O X X . . X . X O . . |
$$ | . . . . . . . . . . . O O . O X O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . X . . . . O . O O . O . . . O X X . |
$$ | . O O O O . . . . X . . . . . O X O . |
$$ | . O X X X X . X . , . . . . . O O X . |
$$ | . O O X . . . . . X . X . . . O X . X |
$$ | . X X X O O . . . . . . . . . O X X . |
$$ | . X O O X . . . O O O . X . X O X . . |
$$ | . X X O O O O . . X . . . X O . O . . |
$$ | . O X O . O X O . . . . X O O O O . . |
$$ | . X O O O X X X X , . . . X X O . . . |
$$ | X . X X O O X . . . . . . . . X O . . |
$$ | . X . . X X . X . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ ---------------------------------------[/go]

Going back to black getting n18 and monkey jump black got 17 points beyond the triangles. So with these 3 gotes it went from black 17 to white 8 and black 4 ie black 13 to white 8 so difference of 21 or 7 points per move. 21 is close to 22. So seems they are about the same size (though that was with black possibly making a mistake to make L5 bigger than it really was to settle the ambiguous area).

I suppose there's also the meta-gaming aspect that any idiot 15 kyu up can see that n18 is a very big move, but l6 area is the kind of move you might miss the true size of, so if I want to bet on my opponent's lack of strength I could take n18 for myself and hope he doesn't see how valuable l6 is and then I can grab it later than I should if I assumed I was playing someone who will punish my mistakes.

While Uberdude was posting his analysis, I did mine: two difference games (attempts, I'm 15 kyu at it) and one Kata move analysis in 1 sgf.



Edit: I now realize they aren't really difference games

While people are still thinking about Uberdude's and Knotwilg's analysis, here's another position from Shirae's book. This one is for reading, not counting, and I'm asking because I actually don't know the answer...

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[go]$$Bc Black to steal lots of territory from white
$$-----------------------+
$$ . . . . . . . . . . . |
$$ . . . . . X . . . . . |
$$ . X . X . . O . . . . |
$$ . . . . . O . O O O . |
$$ . . . . . . . . X O . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . X . . |
$$ . . . . . . . . . . . |[/go]

The book solution is a move that wasn't on my radar: But my question is: if black tries at one of these two alternative points, I can see that black is thin and there's more than one way for white to punish black, but what is white's best continuation?

A complication in this one if the white group has spare eyes in the centre such that white can ignore black's move in the corner as a pure gote yose, then bad move 1 actually has a bigger followup than the 'correct' move, in that s18 next actually makes a few 1st line points for black and white can't make 1 eye in sente at q17.

There are so many variations, I don't know what the best response is but here is an attempt. If someone finds a mistake or a better response I would be interested.

xela wrote:The book solution is a move that wasn't on my radar:

$$Bc
$$-----------------------+
$$ . . . . . . 1 . . . . |
$$ . . . . . X b . a . . |
$$ . X . X . . O . . . . |
$$ . . . . . O . O O O . |
$$ . . . . . . . . X O . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . X . . |
$$ . . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$Bc
$$-----------------------+
$$ . . . . . . 1 . . . . |
$$ . . . . . X b . a . . |
$$ . X . X . . O . . . . |
$$ . . . . . O . O O O . |
$$ . . . . . . . . X O . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ . . . . . . . . X . . |
$$ . . . . . . . . . . . |[/go]

jlt wrote:There are so many variations, I don't know what the best response is but here is an attempt. If someone finds a mistake or a better response I would be interested.

I had different move orders which I think come to the same result!

If black plays the one-space jump: If black plays the knight's move: