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"Black left the game"

It happens a lot of the time on lichess that when you are going to mate the opponent on the next move, they go offline and then you have to wait a long time before the opponent forfeit.

Example:



Can the server detect when you have mate next move, opponent disconnect, and then forfeit them immediately? It's a drag..
That's what the 2100 level of blitz is like? My opponents don't disrespect me like that, I'm really sorry to see that occuring. Maybe there is something to do with increased levels of performance and increased levels of stress and disrespect? I'm really not sure why you would be experiencing this often, because none of your opponents should ever disrespect you enough not to resign before leaving. I guess sometimes it happens.
Yeah that’s not right. If they just know they are going to lose they shouldn’t be sore losers and leave to game
Very annoying, but a balance has to be struck. The more you let the server intervene in situations like this, the more often injustices will be done.

In this particular case there's no reasonable doubt that White should be given the win, but putting that into software may result in other cases where a player loses the connection, the server sees that it's mate next move and gives the opponent the win before the connection can be restored, but that particular mate is actually hard to spot for human eyes and might not have been played.

Or suppose it's regarded as reasonable to assume that the opponent of a disconnecting player will always see a mate-in-one and you build that into the software. What about a rather simple mate-in-two? If your opponent had disconnected on move 31 instead of move 32, should you have been immediately granted a win then? Where do you stop?

The balance which is struck at the moment is that a disconnecting player is given a reasonable time to come back (how much time depending on various factors including the time control), then the game gets forfeited and the disconnecting player given a warning. If those warnings mount up, sanctions ensue so that the offending player can't play games for a while. This minimises the chance of penalizing bona fide players for their dodgy connections while still doing quite a lot about the problem of players who leave the game instead of resigning. And I think this balance is about right.
@Brian-E It doesn't have to be so naive. You can detect users that have a *pattern* of disconnection immediately before a loss, and begin to forfeit those users when there's sufficient evidence that it's not coincidental.

A user who does this 100x more than the average user is surely doing it intentionally. I mean look at Omarkhraisat93's most recent game (v Feder1020) the same user have just did it again a few games later, seems like a habit ..
I hate when that happens once I was losing and the opponent left the game and then I was so happy and then at 10 seconds they came back in the game I was so annoyed.It was like they were trolling
@wg2024 said in #5:
> It doesn't have to be so naive. You can detect users that have a *pattern* of disconnection immediately before a loss, and begin to forfeit those users when there's sufficient evidence that it's not coincidental.

There's nothing naive about striking a balance. This pattern detection is certainly already done and will be applied both to the amount of time given for a player to return after disconnecting and to the tolerance level before warnings are replaced by serious sanctions.