The most useful play in go is one that most experienced beginners pick up unconsciously. It is not necessarily a big play, but it is a workhorse. It occurs frequently[1], in all phases of the game, from the opening to the endgame. It does not even have a name, but its variants have names. For convenience I call it the press.
Now, the word "press" is already used for a different play, but that's all right, because if you talk about it in a game, you won't call it a "press", but will use the name of one of its variants instead.
If you are a new go player, learning about the press will give you a leg up. It is a simple play, but learning the reasons for playing it will help you understand some ideas about the game.
This is the press. The stone played in the press () is adjacent to one friendly stone (
), one enemy stone (
), and two empty points at right angles.
First, the press takes away one liberty from the enemy stone (along with any stones it is firmly connected to). It may even capture it (or them). If that stone is not yet alive, it weakens it.
Second, the press typically adds one liberty to the friendly stone.
Before the press, has a liberty at a. Afterwards it has two liberties at the b points. The press adds one liberty to it unless one of the b points is already one of its liberties through the stones connected to it. If
is not yet alive, the press typically strengthens it. It may even give it life.
Third, the press exerts influence on the adjacent empty points, as a rule.
Whether exerts any influence, and how much, depends upon the surroundings. Here I shall talk about the typical case.
exerts the greatest influence upon a. Typically it cuts off
from it. It may even make it territory.
typically exerts less influence upon b. If c is empty, too, we may get the following sequence of play:
After ,
cuts. We do not know the effect of the cut without seeing the surroundings, but typically it separates
and
, weakening both.
In summary, the press typically weakens the enemy stone, strengthens the friendly stone, and exerts influence on empty points. That is why it is such a workhorse. These are basic aims in go. Even if it does not accomplish all of these aims, it will usually accomplish one or more of them. Typically it will accomplish more than one of these aims. In general you should try to make multi-purpose plays.
Here I give ten examples from top level play.
Example 1, Block
This example comes from a game between Dosaku, White, and Doetsu.
This variant of the press is called a block. Feel the power of this play. It strengthens and puts pressure on
. In addition, its influence extends beyond the adjacent points and works with
.
Example 2, Push
Later in the same game.
is a variant of the press called a push, as is
, for obvious reasons.
The push is often defensive in nature. Here and
strengthen
and, with
, make territory in the corner.
Later in the same game.
The blocks, and
, work with the
stones to create a framework. To appreciate the power of
, compare it with a White play on that point (next diagram).
Example 4, Turn
is a variant of the press called a turn. It is very big here, weakening the
stones severely while working beautifully with all the White stones on the right side.
Example 5, Crawl
Later in the same game.
is a variant of the press called a crawl, again, for obvious reasons. Here it takes away a little bit of potential White territory on the side, but mainly it produces a weakness for White, the cutting point at a.
Later in the same game.
strengthens
. Together they radiate influence towards the center, working with the other White stones facing the center.
Example 7, Atari
The following examples (7 - 10) come from a famous game between Shusai (White) and Go Seigen.
has characteristics of the block, but its most salient feature is that it threatens to capture
. So we just call it an atari.
(Sebastian) Even though it forms an empty triangle it is a good move because it retains sente for White.
Example 8, De
pushes into Black's position. Such a play is called a de. With a de the main influence is forward, in this case at
.
Note that if Black had the move he could seal territory off with a block at .
blocks against Black's hane,
, and threatens to take the stone.
saves it.
If White ignored the hane, Black could play a crawl at .
blocks, putting some pressure on
and preventing a de at
.
See also Introduction to the 'touch' tactic
[1]
Between 10% and 15% of the time, or so.