Questions about a 3-3 move in a pro game

judicata · #1

I came across the move below in a recent pro game (Fan Tingyu vs Park Junghwan, June 22, 2013), and it surprised me a little. I haven't checked my database (which includes GoGoD) for how common it is, but I'm wondering if anyone has thoughts about this move over 'a'. I guess the game move makes sense because (1) the approaching black stone doesn't really have any more breathing room than it would if white played 'a'--that is, it isn't leaving any eye space, and (2) the game move makes an approach on the other side easier to handle. Does this sound right? Any other thoughts?

Click Here To Show Diagram Code: [go]$$Wm30 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . a O . . . . . O . . O . . , . . .| $$ | . . 1 . . . . . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

Bantari · #2

Interesting, I have not seen it before.

Click Here To Show Diagram Code: [go]$$Wm1 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . c . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . b a O . . . . . O . . O . . , . . .| $$ | . . 1 . . . . . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

White '1' as opposed to 'a' gives Black a nice slide at 'b', so there must be some good reason for White to make this concession. The only thing I can think of is the following:

The natural move for Black later (or immediately) is the jump at 'c'. Looking at the position after 'c' in both cases:

Click Here To Show Diagram Code: [go]$$Wm1 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . 4 . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . 2 . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . 1 O . 3 . . . O . . O . . , . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

In this case White's natural answer is at '2' or Black can invade there. After that, 4 might be a good move for Black.
On the other side:

Click Here To Show Diagram Code: [go]$$Wm1 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . 4 . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . 3 . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . 2 . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . . O . 5 . . . O . . O . . , . . .| $$ | . . 1 . . . . . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

With the White stone at '1' here instead, White might feel more freedom to switch to the left instead and play there. With the possible sequence of '4' and '5' - possibly later in the game. So is it a matter of whole-board strategy here?

In either case, I lack the skill to properly evaluate which is superior in this overall position, but I have a feeling that White 'a' in the initial diagram and subsequent strategy is much more common in pro games than the actual '1' played. It seems that this might be another one of the 'new move' experiments. Lets see how successful will the history judge it.

mhlepore · #3

I found 56 instances of it doing a pattern search on the badukmovies.com website.

It looks like a move a 20 kyu would make and get criticized for, but seems to give the opponent less forcing moves locally.

judicata · #4

mhlepore wrote:

I found 56 instances of it doing a pattern search on the badukmovies.com website.

It looks like a move a 20 kyu would make and get criticized for, but seems to give the opponent less forcing moves locally.

I still haven't had time to load up my larger database, but according to SmartGo Kifu, the 3-3 move is more common than the move I marked 'a'. SmartGo Kifu doesn't have the ability to adjust the pattern area and find matching games, so I don't know how representative that info is, but it is a data point.

Kirby · #5

I have no idea what pros think, but before I read your description, my gut feeling was that the 3-3 was better than 'a', because with 'a', I feel bad about an invasion around this area:

Click Here To Show Diagram Code: [go]$$Wm30 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . O O . . . . . O . . O . . , . . .| $$ | . . . . . B . . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

To me, if I have the 3-3 instead, if black does the same invasion, I feel like the corner is more or less "settled" and I can concentrate more on whipping black up:

Click Here To Show Diagram Code: [go]$$Wm30 KILL $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . . O . . . . . O . . O . . , . . .| $$ | . . O . . B . . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

From here, I don't know the best attack, but my intuition says that I can hurt black more since the corner is settled on the left. Black may not play this invasion immediately, but locally, the 3-3 just seems better here.

Contrast this with the situation where white has another stone on the bottom (not really a fair diagram since black hasn't played an extra move, but just to illustrate):

Click Here To Show Diagram Code: [go]$$Wm30 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . . O . . . . . O . . O . . , . . .| $$ | . . . . . . O . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

Here, locally, I feel much better about playing 'a' than the 3-3:

Click Here To Show Diagram Code: [go]$$Wm30 $$ +--------------------------------------+ $$ | . . . . . . . . . . . . . X . . . . .| $$ | . . . . . . . . . . . . . O X O O . .| $$ | . . . . . . . . . O . . . O X X O . .| $$ | . X . O . O . . . , . . . . . X . . .| $$ | . . . . . . . . . . . . . . . X O O .| $$ | . . X . . . . . . . . . . . . X X X .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . , . . . . . , . . . . . , . . .| $$ | . . . . . . . . . . . . . . . . X . .| $$ | . . O . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . X . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . X . . .| $$ | . . W O . . . . . O . . O . . , . . .| $$ | . . . . . . O . . . . . . . . X . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ | . . . . . . . . . . . . . . . . . . .| $$ +--------------------------------------+[/go]

I dunno. This is just my gut feeling, but it's kind of a strong gut feeling. Then again, I just had lunch, so maybe it's bad digestion.

Questions about a 3-3 move in a pro game

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