I have played as white in this 9x9 game: https://online-go.com/game/16296789
Obviously my opponent tried to invade into the upper territory. However, he stopped this and passed and so did I. I considered the upper territory to be mine as long as my opponent does not proceed the invasion.
So, once the selection of dead stones was displayed, I marked the black invader as dead and pressed “accept”.
After that my opponent did something and the game ended scoring the entire upper group as dead.
There might be a way to kill it (too complicated to predict for a player of my rank) but as long as that did not happen and both players pass, it should be white’s, shouldn’t it?
Furthermore, I would expect the game to continue if there is a conflicting understanding of a group’s status. Instead I just died and the game ended.
Can someone explain why?
Your top territory (although you do need a move to turn it into territory) isn’t marked as territory, ostensibly because the black stone at E8 isn’t marked as dead.
You’d have to ask the developer of that client in that case.
Your opponent can mark his stone as alive, but it prevents you from accepting the score for 2 seconds. Always make sure the correct score is displayed before you accept.
It does not matter how it was rated so much. It was most likely a client error.
However, I would still be interested if the upper area is black’s or white. Any hints?