Could someone please explain how white can capture black. I assume the blacks in question are the stones attached to the left, but I only see how black wins the 5 white stones in 3, whilst losing just two, unless black tries to save all.
The puzzle Learn to Play Go looks wrong.
I don’t see the problem. The question is about how many liberties black has, not about who wins the capturing race. If you don’t understand that black has 4 liberties, and that one of these liberties is the 6-4 point, then you are likely to connect at the 6-4 to save two stones and thereby lose the entire group.
This works, I think.
B A3 - W A6 - B A2 - W E7 - B A1
Ah, yes. White needs 4 moves, so will lose the capturing race.
before I want to talk about the actual problem, i want to take a look at this one: problem 5
The obvious solution is “2”, which is correct. But normally white is completely dead in the corner, which means, the structure of these problems is to consecutively make a legal move until the black stones are captured.
following the actual problem 6.58 / 9:
Which the logic from above, white needs 2 consecutive moves to capture the 2 stones, which can already be counted as “i captured black” → this answer is not available.
White would need 3 consecutive moves to capture the big group on the left, which is the big and obvious group to capture → this answer is marked as wrong, but it should imho be correct
If white wants to capture the big group + the 2 stones, the answer would be 4 → which is marked as correct.
with 5 consecutive moves, white could capture the bottom group, with 7 consecutive moves the bottom group + the right stone. → neither is correct.
I find this problem a bit misleading or I don’t understand something on a fundamental level about these.
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Oh I see. The title “Capturing race”, together with “White to play (…)” suggested that White and Black play alternatively, so the sentence “(…) to capture Black” looked wrong, since White can’t capture Black if both play alternatively. It would be clearer to ask “if White could play several times in a row, how many moves would White need to capture at least 7 stones?”
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While I understand the inconsistency you’re gesturing at, it’s bad semeai technique and bad endgame for white to remove a liberty from his corner group in 6.58.9.
There are multiple senses of “liberties”. There is the literal meaning of liberties to which the rules of Go apply (the empty spaces adjacent to a chain of stones, which when decremented to “0” result in a capture), and then there is the effective number of liberties which you need to win a capturing race. Effective liberties include approach moves. Some approach moves are strictly necessary in order to make it legal to play a stone on one of the (literal) liberties, and others are only tactically necessary, because reducing the (literal) liberty directly allows the opponent to recapture immediately, or otherwise defeats the purpose of reducing his liberties by reducing the liberties of your own vulnerable stones as well.
The reason the problems say “how many moves does White need to capture Black”, I assume, is to gesture at the concept of effective liberties (i.e., the number of moves W needs to play to capture B with good technique), to train people to count effective liberties correctly and thereby predict the status of capturing races, without getting beginners confused about this ambiguity of the concept of “liberties”.
I understand that you feel semantically “how many moves” should mean only a subset of effective liberties (“smallest number of consecutive moves to capture, if you’re sure B won’t respond”, or in other words the literal liberties plus any legally necessary approach moves), but in practice this very precise distinction isn’t useful for teaching beginners about capturing races. Where it does become important is in extremely large ko fights, where sometimes you play “bad technique”, point-losing ko threats in order to create an immediate threat to capture.
