Life In 19x19

Maybe just conclude that the connection on the 2nd line is more "shapely" than the third line, and make that your first choice move when assessing options. This choice comes up often, as the two space jump on the third line is an extremely common move.

Here is a related position I came across yesterday: go to move 51.



I have noticed that in such instances the pro typically plays the triangled move, leaving two cuts behind, whereas the typical amateur tends to opt for the safer aji of A. That aji is quite strong, actually, as after a cut at A White has a standard but good attachment at B, and that was even played in this game.

It seems very rare to see a comment on this choice and I have always assumed it's down to pros taking the trouble to "read" deeper whereas we tend to play with much less time and so take the safer options. I say "read" in quotes because it's usually not possible (as here) to read out specific lines, but there seems to be rather more envisioning of the future than just evaluating the position. (Incidentally that's one reason I don't have much truck with the school that makes a binary distinction between "you first evaluate a position" and "you must read out the next play." There is a hazy in-between.)

Anyhoo, I was surprised to see a comment on this move by the player, and he said that the triangled move at A would leave better aji for later but then the relationship with the area above would become "very different."

Unfortunately that's all he said, and it leaves some things hanging dreadfully: what are the relationships above, and why "very" different as opposed to different, and why no mention of the side relationships?

On the other hand, reading between the lines, we can infer from the lack of self-reproach in the comment that he was happy with his choice (and Black did win). There may be clues in the final position, but frankly, to me, Back's choice just seemed to help White get a big centre more easily. One reason for such moves in many positions is to take a liberty away from the opponent, but here move 51 still leaves White in a "five alive" liberty situation with no Black stones remotely in the offing, so I assume the choice was 100% strategic.

So what do you think Black saw in the position that made him choose 51 over A?

I have no idea, John. P2 seems better to me, too, but I must be missing something.

Locally, the move in the game "feels good" since it takes away liberty and is closer to the center. But as you point out, from the aji, black was sealed in anyway.

Maybe he had the option of giving up the corner? But he didn't.

I don't know.

I don't know the answer, but a few thoughts:

1) White's cut is nice for the outside, but it gives up some points.
2) Black is taking a liberty, which while not important now can easily become important later.
3) Black is locally alive, but White's hane in the corner may become sente later if he plays the "safe" move. If he plays as in the game and White cuts, there will never be any issues with living.

When I've played with this position before, I noticed that none of Black's potential moves are really satisfying: the second line move "feels" slow, the move played here leaves the cut, connecting in the corner leaves a soft outside.

John Fairbairn wrote: I have noticed that in such instances the pro typically plays the triangled move, leaving two cuts behind, whereas the typical amateur tends to opt for the safer aji of A. That aji is quite strong, actually, as after a cut at A White has a standard but good attachment at B, and that was even played in this game.

I looked up the position in the lower-right corner (searching a 9x9 sized corner).
The 3rd line connection doesn't even appear once, it is mostly the 2nd line one (first choice), then tiger-mouth on the inside (2nd option).

Only when searching on 7x7 I get one game where the 3rd line move (like in the game you posted) appears, but there is an enemy stone nearby (and the game is quite advanced, as in many moves played) which may have influenced the choice.
(Obviously, I don't have the game you posted in my database).

So, what you call "the typical amateur move" is also the "typical pro move" in this case