Obviously, we always have to keep our eye on the whole board, but my guess is stronger players develop an “intuition shortcut” for vulnerable groups.
In tsumego problems, usually we are told that B is to play and capture/kill, so we go in already judging those W stones for their weakness while plotting their downfall.
However, in problems from real games, unless it’s something obvious like an atari, more often than not I can’t pinpoint a group of stones with promising weaknesses. Killing an isolated group may even be the easier of the two, because we’re looking for eye shape, if it isn’t there that group is hopeless. But just plotting to take those 3-4 stones? That’s tougher.
What usually clues y’all in that a group is vulnerable and, if possible, in what order?
Obviously I don’t know since I lose stones on a regular basis. In-seong Hwang has written a book, “Trouble Master”, and I’m quite bad at those problems.
Anyway the first thing to look at is
count liberties
visualize what happens if you make all possible ataris and all possible cuts
and don’t forget to read variations.
Results not guaranteed.
Shape. That’s why Tsumego is important. If you know a certain shape is killable, you can recognise it immediately on the board. Even if the shape is not exactly the same, it will give you some ideas when you are trying to read the variations.
Shortage of liberties and cutting points are also good clues, but I think they just tell whether the aji is bad or not. If you are talking about whether a group is killable, identifying the shape based on the Tsumegos that you have done will help a lot.
Full board is not tsumego. Its often possible to capture group that always possible to defend. Because opponent may decide that he will not defend that group, there is more important move in other place. Or because he just fails to protect it.
Open any dan+ level tsumego where you need to create 2 eyes. Its always possible, but you will fail. Therefore if you see similar group of your opponent, you will know: he will fail to protect it too.
Eyes. Or a possible seki.
It’s mostly reading and experience on where are the efficient attacking moves. And the efficient way to get life too (contact moves, sacrifices, vital points…)
At low level it’s often a simple disagreement on status or even some greediness. Later it’s more about the follow up (I’m dead here but), killing is not always the right choice.
I have to say, although I’ve mentioned that I’m having more difficulty with groups of stones that are not necessarily about life (it could be a group of stones that are vulnerable to be cut off but not necessarily kill something) y’all focus on killing.
Is this a prerequisite, as in, you don’t really check for what I’m asking (capture a small group that wasn’t going to live on its own anyway), only for what is killable?
I found significant that you mentioned cuts. A direct cut is not always the way to attack you can have threat for multiple cuts for example which could be more efficient.
The O stone will usually be in a better place as a cut in the ∆ places.
If you mean these fights between disconnected and isolated stones, beyond reading, it’s mostly about outside liberties, who has more. I hope this answers your question.
I rarely think about killing a group outright. I try to identify groups that look weak, and aim to profit off attacking them. Often you can get more points chasing a weak group across the board than from killing it. Though, if it should happen to die, that’s fine too I’ll usually only start consider actually killing if it’s already fully surrounded or else if it’s a super deep invasion into a fairly strong moyo.
I’m not sure if people are having the same sort of scenarios in mind as you do. Like, it doesn’t happen very often in my games that I even have the option of outright capturing/killing something. If it happens, it’s usually just some sort of trade without any surprises for either player.
So perhaps it’s better to discuss some specific example situations from your games, rather than trying to get some general advice (where the answer is probably an unsatisfactory “it depends”).
You might check out the book Attack and Defense. I find it’s a good explainer for the philosophy behind killing. It’s not about how to kill a group, but it about how you profit by using weak and strong groups, regardless of whether you kill.
When i’ll judge whether i can attack and maybe even kill a group, i’ll go thru some questions like this:
Is that group alive even if i play something against it and they tenuki, or do they need to answer?
If they do not tenuki, what is the best ‘attack+responce’ combination for me? (unless there is a clean way to kill, its often smarter to force the the opponent to live in gote instead throwing wishy-washy invasions which might die inside their territory)
Or after its clear that a group is under attack and potentially killable, like it cannot expand its eyespace or connect into something else,
where is the eyespace and what is in “the middle of it” as thats usually the vital placement for L&D?
If they have 2 potential spaces for eyes, are there any way to falsify one of them?
If the group still looks safe, does anything change when all the outside liberties and dames have been played? If some cut or snapback emerges, which are the liberties that make it work?
if nothing else seems to work, which moves are the best ko threats against the group?
That being said… I feel like most kills that happen on my games have been big suicadal accidents and there has been no planning involved whatsoever xD
Most of the time i just notice opponent playing something that “looks a bit odd” and then everything suddenly blows up. Or i have read out that they need to answer my approach/attack but instread chose to tenuki ^^
If it’s about killing groups, if the group has two eyes, it usually can’t be done (except if they sacrifice it).
If the group can live with one move, and it’s not surrounded yet, it probably wont be killable.
But that brings the next point, which is that whether a group is weak or strong depends on its surroundings and eyeshape in combination.
A group might have no eyes, but if all the surrounding stones are weak, cutting points, liberty problems, or can be counter attacked or surrounded, then maybe the group can live easily.
If a group is solidly surrounded by stones with no weakness, or the group can escape into an area but that area is full of strong stones of the opponent then there might be potential to kill it as long as it doesn’t have clear eyes.
Then lots of Tsumego techniques kick in, falsifying eyes, making dead nakade shape inside, poking at shape, or taking vital points etc.
But yeah if it’s about smaller groups of stones, or parts of groups then
Liberties being low a lot of the time indicate tactics/tesuji, or at least places worth looking.
The “all possible ataris and cuts” is good advice because they’re forcing if the player doesn’t want to give anything up. There might be other kinds of forcing moves too like peeps to prepare cuts and other threats like laddering threats or cutting threats, or some combination of double threats.
Sometimes just imagining what happens if you get two moves in a row also helps to visualise issues and tactics. It can happen in kos, when the player tenukis, but also sometimes an answer is indirect, like you threaten a cut, but they just try to surround rather than answer the treat by connecting attaching or some other very near by contact play that can affect liberties.