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Don't know what it's called but see it often.

Posted: Fri Oct 01, 2010 5:13 am
by DIV
Is there a name for this type of move on the edge and what are the best ways to hinder it's progress?

Re: Don't know what it's called but see it often.

Posted: Fri Oct 01, 2010 5:24 am
by Li Kao
I usually see the (big) Monkey Jump and not the small one you showed:
http://senseis.xmp.net/?MonkeyJump
http://senseis.xmp.net/?SmallMonkeyJump

Re: Don't know what it's called but see it often.

Posted: Fri Oct 01, 2010 5:27 am
by Stable
Ninjad by Li Kao!
Here the big monkey jump would be gote (it's often sente) but with proper play you can get sente with the small monkey jump/knight's move

Re: Don't know what it's called but see it often.

Posted: Fri Oct 01, 2010 5:33 am
by gowan
A Monkey Jump usually can't be captured unless the jumper makes a mistake. The right way to block further progress is not a simple thing and depends on the shape of the nearby stones. There is information on this at SL and there is a Slate and Shell book by Richard Hunter called Monkey Jump Workshop that discusses the details. One of the big issues is whether the jump is sente or not.

Re: Don't know what it's called but see it often.

Posted: Fri Oct 01, 2010 2:42 pm
by DIV
Thanks very much all.

Re: Don't know what it's called but see it often.

Posted: Fri Oct 01, 2010 4:01 pm
by ethanb
gowan wrote:A Monkey Jump usually can't be captured unless the jumper makes a mistake. The right way to block further progress is not a simple thing and depends on the shape of the nearby stones. There is information on this at SL and there is a Slate and Shell book by Richard Hunter called Monkey Jump Workshop that discusses the details. One of the big issues is whether the jump is sente or not.



True, but there are generally three moves to look at before deciding that everything's lost and it's too complicated. :)

Click Here To Show Diagram Code
[go]$$Wc
$$+-----------
$$|.X...1b....
$$|....ca..O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


In 80% or more of monkey jump situations (including this one) A is the correct answer.

It continues like this:

Click Here To Show Diagram Code
[go]$$Wc
$$+-----------
$$|.X..41a3...
$$|.....2..O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


Then white can decide whether or not to connect at A immediately - sente might be worth more than the 2.5 points offered by connecting.

White can also connect by playing at A instead of 3, but then if he plays elsewhere after 4, black can catch 2 stones.

The B answer in the original diagram is sacrificing a stone to make sure you have a sente atari (usually in life-or-death situations.)

The answer at C is for when you have lots of stones on the fourth line and probably should have blocked the monkey jump instead of waiting to play this. :)

In special situations (less than 1%) you may play a move other than these three, but almost always the answer is A, if not then B, if not then C.

Re: Don't know what it's called but see it often.

Posted: Sat Oct 02, 2010 10:28 am
by Bill Spight
Interesting example, ethanb. :)

Click Here To Show Diagram Code
[go]$$Wc
$$+-----------
$$|.X..b1.c...
$$|.....a..O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


I think that "a" and "b" are usual replies in this kind of situation (Black stones on the 3d line). "c" is also possible, as are other plays.

Click Here To Show Diagram Code
[go]$$Wc Sente follow-up
$$+-----------
$$|.X4351.....
$$|...6....O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


White has a sente follow-up, which threatens to kill the Black group.

I think that Black's reverse sente depends upon the ko threat situation.

Click Here To Show Diagram Code
[go]$$Bc
$$+-----------
$$|.X..5O.4...
$$|.....1..O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


If White is komaster, then Black's move is :b1: (or :b5:). Later :w4: - :b5: is sente.

Click Here To Show Diagram Code
[go]$$Bc
$$+-----------
$$|.X...O32...
$$|.....541O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


But when Black is komaster, or often when neither player is komaster, Black has a somewhat unusual play with :b1: - :b5:. (Note that unless White is komaster this normally stops White from going further into the corner.)

Click Here To Show Diagram Code
[go]$$Wc
$$+-----------
$$|.X...O21...
$$|.....B34O..
$$|XXXXXXXXO..
$$|OOOOOOOOO..
$$|...........[/go]


Alternatively, Black can play the usual response, and if White plays :w1:, throw in with :b2:.