Go društvo Ljubljana

“When you realize that no stone matters you will become strong
- when you realize that every stone matters you will become even stronger.”

As with every go concept and most go proverbs the truth hides in the contradiction, in the balance of things.

Go is a game of balance. The contradictory nature of the proverbs that is so confusing to the beginners is a natural consequence of the nature of the game. You have to develop your influence rapidly but not become thin, you need to play thick but not become over-concentrated and you have to strike a balance between taking big points and leaving bad aji in your position behind.

Yet there is another way to look at the game of go. At the end of the game both players played the same number of moves and the player that used his stones more efficiently will be the winner of the game. I hope this concept of the efficiency will lead the reader to better understanding of the game of go and hopefully to use your stones to their maximum potential. Let us begin this journey with an endgame problem.

An endgame problem

Diagram 1: Black to play and win (komi 0.5)

The position in diagram 1 is one I created after reviewing a game between two relatively strong players. It is an endgame problem but at it’s basic level this is a problem about the efficiency of ones stones. The territories in this “game” are quite developed and it’s easy to count the score and to identify the remaining points of play as well. Strong players will surely have no problems in solving this problem but let me offer a hint at the solution.

Try to use your stones to their maximum potential and remember that there is a ko left to play.

Diagram 2: Unimaginative play

First lets take a look at how the game was played out by players who did not use their stones efficiently. is an unimaginative play. It is a move that retains sente but that is all this move accomplishes. White naturally connects at and the game continues with each player playing the biggest moves on the board. By move it is clear that white has won the game and that the outcome of the ko fight will bear no relevance to the outcome of the game.

As we proceed to the next diagram please bear in mind the - and the - exchange.

Diagram 3: Improvement but...

This diagram is a considerable improvement on the sequence of play.

Black play at shows black understands there is no need to play the vulgar move in diagram 1. It might be instructive to see why. Weaker players might think playing 1 space above will gain white more territory but in fact black will just play 1 space above and white will be forced to connect at either side of the . Realizing this, white makes a seemingly submissive play at which is the winning move.

With white the ko fight starts again. Black has one ko threat at a but white has another-one at b so white wins the ko and the game by 0.5 points. The result suggests black made a mistake in his play and the next diagram will shed some light on this and the curious move white made at .

Diagram 4: The correct sequence

This diagram shows the correct sequence of play.

The first thing you have to realize is that with the - exchange white territory on the bottom side stays the same. It might be helpful to think of this exchange this way:

• Black exchanged - which gains a point just like - gains a point in diagram 2;
• Black & forced white to answer at & so the territory does not change by this exchange;
• Black plays in sente which prevents white to play in diagram 2.

The rest of the game follows naturally and with the ko fight starts. Comparing this diagram to diagram 3 it becomes clear black gained a second ko threat at c and therefore wins the ko and the game by 0.5 points. This diagram should make the reasoning behind in diagram 3 very clear. It is the only move that leaves no ko threat for black on the bottom side. It is also very important to understand that black must sacrifice both stones to gain the final ko threat and I leave it to the reader to realize why.

It might seem like a small gain but every point and every ko threat is important and may change the outcome of a game. For the readers who feel this example is too remote or artificial it will be instructive to take a look at the next example.

To sacrifice or to hane?

Diagram 5: Black to play

This is a common position. In the endgame stage it will be blacks privilege to play first at the bottom side however the sequence of moves black makes is quite important. Will a simple hane do?

Diagram 6: An ordinary sequence

In this diagram black plays a simple hane and white connects. This seems a perfectly rational sequence and most players find this an easy position with no further explanation needed. Following the - exchange it becomes whites privilege to play in sente as black must connect at .

Diagram 7: Efficient play

In this diagram however black sacrifices a stone and after the exchange - it is again whites privilege to play at in sente. In terms of territory diagram 6 & 7 are identical but the value of black sacrifice is visible as an additional ko threat at a.

Diagram 8: An unlikely sequence

There are however two crucial considerations black has to weigh before choosing diagram 7 over diagram 6.

First of all, you may have noticed that the capture of black stone makes white thicker in diagram 7 and if this is of any importance black should not blindly sacrifice a stone. Normally these moves are played in the endgame stage so this is rarely the case.

Second of all, with the sacrifice black loses the option of playing as in diagram 8 (which is 1 point better for black then diagram 6). This however is an unlikely sequence as in diagram 6 is a (1 point) sente move for white while in diagram 8 is a (1 point) gote move for black. Once you know where to look, your vision opens up and interesting positions start to appear everywhere. Lets look at the next example.

Diagram 9: Efficient sacrifice

This is a simplified position from one of my games. My opponent was black and the game was well into the endgame stage.

At first glance the position seems settled, white will eventually connect at a and black will have to connect his lone stone at b. However it was my turn to play and I believed there was more to this position that meats the eye.

Diagram 10: An efficient sacrifice

White continued with a sequence -. With the position now truly settled white is left with ko threats at c and (after black captures) at d. Had white played as mentioned in diagram 9 there would be no ko threats left. But there’s even more to this story.

Diagram 11: A ko threat for black

In diagram 11 black plays at which threatens to play at e forcing white to connect at f. If white connects at e black effectively removed two white ko threats in sente. It should be clear that a move like should not simply be counted as a 1 point gote move and that white must not miss his opportunity to play as in diagram 10 quite early in the endgame. There is value in every move that is played and sometimes the value remains on the board as a lingering smell even after the stone is long gone. In the above examples the sacrificed stones had a subtle effect, they did not lead to immediate territorial gains, yet they are our first step in our journey to better understanding what it means to use stones efficiently. We will continue with more lessons in efficiency in section 2 where we will look at sacrifice techniques in more detail.

©2001 Goran Šiška