Pincer

In a corner opening, in response to the kakari of , or a nearby move is called a pincer, because it “pincers” the approaching stone from the other side. The pincer is an attack on , and prevents it from forming an ideal base.

There are many possible consequent developments:

a) jump out to defend the pincered stone

b) lean against the corner stone to develop strength towards the centre and left side

c) lean against the pincer stone to develop strength towards the corner and top side

d) attach to the corner stone to make a living or flexible shape

e) invade the corner and sacrifice the pincered stone, or link up with it should the opponent choose to block at the top

f) double approach to the corner stone

g) counter pincer

Overview

All types of pincers are indexed by the pincer path.

The article Pincer Nomenclature explains the terminology for pincers (“low” v. “high”, “n-space”) and provides links to many josekis arising from pincers.

There are three common sources of pincers: the 3-4 point, the 4-4 point, the 3-5 point when the approach is at 4-3. There would be a certain logic in treating 4-4 point double kakari variations as pincers. Uncommon pincers are:

• 3-3 point pincers.
• 3-5 point 3-3 approach pincer.
• 3-5 point high approach pincer.
• 4-5 point pincers.
• the missing pincer: two-space low pincer after 3-4, high approach.
• 3-6 point pincers: mostly seen in amateur go.
• zero-space pincers: up close and personal.

prevented Black from making an enclosure, and then prevented White from making a base on the third line. White would like to extend at least to . A three-space pincer at a would allow White to extend to b, which is a cramped short extension. White now typically played in an open corner, satisfied with having prevented a black enclosure.

Later, people realized that Black need not hurry to attack . If Black played in an open corner and White extended from to make a base, Black could make an enclosure in the other corner, which was better. Even later, people realized that White did not have to hurry to prevent Black’s enclosure, but could play in the top left corner in a way that worked with a later kakari at . If Black made an enclosure, White could play first in a third corner. Such realizations were the beginning of fuseki theory.