On Page 01 I explained briefly about the mechanics of passing (saying pass, pressing one's clock, or any other form of communication in informal setting.) I also explained that when two consecutive passes constitute an agreement of both players to stop the game and start the scoring process. On Page 02 I went into details about what to do when players disagree.
Now the time has come to tackle this hardest of questions - When to pass?
To start, lets just look at the endgame conditions briefly. Here is a quick reminder of the conditions, as presented on Page 01:
Endgame Conditions:
— Each of the players must, separately, decide that they cannot gain any more points
to be gained by further play!
— Each of the players must, separately, decide that they cannot lose any more points
by passing and thus declining a move.
— Both players must communicate their decisions to each other and then agree.
— Once the above happens, both players pass and the game is over - the scoring process can begin.
Why is it important to distinguish between making a gain and incurring a loss? Well, it is because these two things are different, in a sense. By passing (and thus demonstrating your willingness to end the game), you can miss on opportunity to expand your area or damage your opponent's area, and thus miss the chance to gain points. By passing, you can also miss an opportunity to make an important security move or blocking move, and thus can give the opponent a chance to damage your areas.
So, on a personal level, before passing, you need to ask yourself these question:
In most cases the above questions are relatively easy to answer, sometimes even trivial. However, there are cases when it is almost impossible to tell, especially with regard to the status of groups (i.e. are all the groups alive?) Luckily, 99.99% of the time, the status of the groups is rather easy to determine, and if not, it is usually played out before players pass (just because they are not sure.) So, most of the time, reaching agreement is trivial. The emphasis is here on "most of the time", however. :)
When you are an experienced player, that is!
When you are still a beginner, it may seem like every position is one of the 0.01% of extremely difficult cases, and you probably feel lost and confused in every game. You wait for your opponent to give you a cue that the game is done, but what if (s)he is as clueless as you are? The 4 questions I mentioned above which you should ask yourself when thinking about passing are a good start, but they seem so dry, so theoretical, and not always easy. What do they mean? Really!
Lets translate the above 4 questions into Go ideas which are more general and apply to both players. Here they are:
Let me talk briefly about each of the above issues, and then I will devote a whole page with practical examples to each of them. This way you can get a general idea first, and then, for more clarification, jump into a more detailed explanation.
As already mentioned in my discussion of Go Rules, you must fully surround territories to be able to count them as your own. And this means - there can be no holes in the walls of your territories! It is pretty easy to visually identify any such hones. Just imagine a territory being a water container, with your own stones and edges of the board as walls. If you imagine water leaking out, the territory is not fully surrounded yet, additional moves are needed.
A slightly confusing issue can be here the existance of enemy stones inside territories surrounded by you. Just think of them as ducks swimming in your water - unless they have two eyes (explained here) they drown and you do not have to worry about them. Lol. I know, I know - it makes little sense for a blind duck to drawn or not, but just go with it. :)
In any case, this issue of blind ducks strongly intersects with Question #5 which deals with status of groups. It is by far the hardest question on our menu, so lets leave it for now and concentrate instead on easier issues, ok?
More details:
You can find more about this issue here.
Now - this is a much harder question that the previous one. And a more interesting one. The basic idea is that of your opponent trying to play inside your fully surrounded territories - can he play so that his stones, his "ducks", survive? Remember - for each of his/her moves, you can make a move of your own, attempting to foil his/her attempt. If for each of his/her moves you make one of your own - the score will not change. Depending on the rules in use (explained here), you might gain points if you find it not necessary to answer some of his/her moves and can pass or play elsewhere instead.
But back to the question.
What it boils down to is this - is there enough room inside your territory to create a group with two eyes? Even
with you trying to foil the invasion at each move, can it possibly succeed?
Usually, for such invasion to be successful, there need to be enough room within your territory, but also there need to be weak points for your opponent to attack - it would force you to answer elsewhere, defending the weak points, while your opponent can get extra moves to strengthen the invading stones. Without such weak points, it is next to impossible to invade a solid territory. And attempts are seldom made. We will deal with the weak points in the next question.
More details:
You can find more about this issue here.
Points that need defending, weak points - there are basically two kinds of those. But most of the time they are easy to spot - they tend to be cutting points of one kind or another (explained here), which means a diagonal relationship between stones.
The two kinds of weaknesses are as follows: the ones you need to defend eventually no matter what, and the ones which only come into play in case of invasion. The first kind, as mentioned, you do need to defend eventually, and the question is only: when? The second kind are more tricky, and you need to figure it out if they really need defending or not. Depending on the rules you use, you might lose a point by defending a weakness which did not need any defence.
Confusing? Right!
Well, in this particular case, a picture is worth a 1000 words. So let me give you some pictures and examples (and tons of words too, just to make sure!)
More details:
You can find more about this issue here.
And pictures, examples, words, etc. :)
More often than not, this is a pretty moot point. By the time both players are considering to pass, the neutral areas are shrunk to single points here and there, or maybe to one-point wide lines - nowhere to gain points (unless you play with area-scoring rules, which are explained here.) In beginners' games, however, all is possible, so we would be amiss if we failed to discuss this possibility. :)
First and foremost, to be able to gain points in neutral areas (under territory scoring - remember, this is what we are using here), it is imperative that the neutral area was at least 2 points wide and 3 points high (2 points high at the edge of the board.) Why? Because this is how much space is needed to surround one point of territory. Assuming the neutral area is adjacent to your own stones. If it is not - forget it, you will not be able to make any pointed there, unless the opponent really goofs up.
The second criteria is - will the opponent be able to prevent you from gaining the point(s)? In a 2x3 neutral area, it is practically impossible to make points, and the opponent can always prevent it simply by playing almost anywhere inside the area. For neutral areas larger than 2x3 points, it might be possible, but it is still very unlikely. If you can see easy (or even possible) ways of making such points in neutral areas, it is definitely a sign that passing would be premature and that the process of dividing the board into territories is not yet completed. So keep playing!
And this is pretty much the crucial point here - if you (or your opponent) can still make points in unclaimed areas, the game is not yet over and it is certainly too early to consider passing.
More details:
You can find more about this issue here.
This is, by far, the hardest and the most complex issue to consider. As a matter of fact, this not only goes for this section and the question of deciding when to pass, but also for the game in general. Status of groups can be very hard, if not impossible to determine in certain situations! And any discussion of this subject goes way beyond the scope of these pages.
Alas, it is still an issue you need to grapple with, if you want it or not, and so I will try my best to present you with some kind of discussion. I'm not scared of difficulties, lol. Or am I? :)
In any case, the core of the question about a group's status is this: does the group have 2 eyes? And, if not, is it possible for it to make 2 eyes? The first question is easy to answer - two eyes are rather easy to identify, and all you need to be careful about are false eyes. I have discussed it somewhat here, as a part of Go Basics section. And so I refer you there to learn about the general concepts of life, death, and the two eyes.
The second question, the one about a "possibility" of making eyes, is the hard one. And the answer can vary depending on who is to play next and often on the overall board position. The important concepts here are the ones of vital points and miai - and I have discussed them here. Also important may be the concept of ko and related ko threats (explained here.)
All in all, it is an extremely hairy issue, the one of status of groups. I will make another attempt at some clarification here, but the real understanding will have to come with experience. Once you a stronger player, the issue is not as difficult, and in most cases the status of each group will be clearly determined by play long before passing is appropriate. For beginners, however, the case is different.
More details:
You can find more about this issue here.
As you can see, the issues and decisions involved in passing range from easy ones (like question of fully surrounded territories) to ones potentially impossible to answer (like the question of status of groups.) How are you, as a beginner, to deal with all that? My advice is to just take it easy - concentrate on what you can understand, on what makes sense to you, and leave the rest for later. Even the simplest of ideas described in this section will help you tremendously in getting a grip on the problem of passing and deciding when to end a game.
More understanding of the complex problems will come with more experience, I promise!