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Strange Things Happen at the One-Two Point
Path: GoProverbs   · Prev: DoorGroup   · Next: EyesWinSemeais
    Keywords: Tactics, Proverb

2-1 points have some particularities, even singularities and the heuristic rules of fighting, learnt on the sides far from the corner, often don't apply here.

One of the reasons is the impossibility to approach from the corner side. This gives the side that occupies the 2-1 point additional tempo to win a semeai.

[Diagram]
Usual way to fight a semeai: Black wins

[Diagram]
Take the 2-1 point first; White wins

Now Black cannot attack from either side because of damezumari.



Another feature of the 2-1 point is the possibity of a throw in tesuji. One of the examples is considered in Stupid Moves. I will show another example.

[Diagram]
White 2 was a small mistake

Black played 1 as a ko-threat. I will not discuss if this was the best threat. White answered 2 giving Black another threat at a. White should have played at a.


[Diagram]
Marked White attacks marked: a direct atari

The marked white stone attacks the marked black stone and is also a direct atari.

The throw-in 1, at the 2-1 point, captures the black marked stone because of a weakness at a.

Actually I can point to a stupid player with White that lost that ko because of this mistake. It was a certain HolIgor (IGS 5k*).

Thank you for correcting mistakes.



2-1 point is a place where many kos happen. For example, the ko that HolIgor (IGS 5k*) lost.

[Diagram]
Black starts ko

Black plays 1 hoping for White's mistake. White sees the ko. White suspects that she wins the semeai without ko (but it is that difficult to read 8 moves ahead, shame on her!), so she decides to fight the ko.

But a sad story of White's mistake has little to do with the topic, and the topic of the page is the 2-1 point. Taking it Black got a ko that saved his group.



The 2-1 point is a critical point in many life and death problems. The difference between living or dying locally is at least 20 points. It is something that cannot be taken easily. That's the difference between winning and losing, or losing and losing badly.

Examples




Path: GoProverbs   · Prev: DoorGroup   · Next: EyesWinSemeais
This is a copy of the living page "Strange Things Happen at the One-Two Point" at Sensei's Library.
(OC) 2003 the Authors, published under the OpenContent License V1.0.