Repeated (duplicate) position error - is this a bug? Unusual seems-like-ko

I quiet don’t understand this “you cannot repeat position” error. Is this bug?
It doesn’t look like Ko.

in history find step 75. Choose it, then try to place black at J8
You will see this odd error.

It shows this odd error, but I used to Ko is when only one(!) stone was at this position, not 2.

You’re game is private so no one can view it except moderators or unless you add them to the list

Oh, did not see this, sorry :frowning: I will grant permission to whoever will ask. As I can see I cannot make game public from the interface :frowning:

It’s a 9x9 game, how about just recreating it as a game everybody can see?

I don’t know how to recreate a game :frowning:

But I recorded video with error (it’s in russian but it basically says illegal position repeat)

One of the rules is that you cannot repeat a previous board position:

In your case, playing J8 would result in the board being in the same position as it was at move 73.

More importantly, you need to understand that all the black stones on the right hand side are captured, there’s nothing black can do to save them. For example white could play J4.

1 Like

So basically Ko rule is part of no repetition rule, yes? It’s not like them both different rules? It was strange for me since it’s not as easy to spot this rule in real life game, unlike Ko.
Also because of repeating board position. It won’t change a thing yes, but why J9 is not forbidden also. Hm. In several moves the position will also be the same

Right, apart from ko these are unusual positions. Recapturing the same intersection (in this case J7) gives you a hint that you might be headed for a repeating position.

Simple answer: J9 doesn’t repeat a previous board position.

Not necessarily, for example white could choose to play J8. Only the move that creates the exact same board position is forbidden, not other moves that might lead to it.

I tried to recreate if there was no rule error here, it seems kinda board can be not totally the same after this move. Or am I mistaken somewhere?