What is lag switching?

I was on C9C9C9C9C9's (one of Andrew Tang's accounts) profile (I had clicked on it after watching an agadmator video on a chess game by him) when I saw that the profile said "lag switching = blocked". What is lag switching and why is it bad?

@A_0123456 said in #1:

I was on C9C9C9C9C9's (one of Andrew Tang's accounts) profile (I had clicked on it after watching an agadmator video on a chess game by him) when I saw that the profile said "lag switching = blocked". What is lag switching and why is it bad?
Lichess offers compensation for lag. in ultra time is important so players switch their vpn on and off to get the compensation and win +1 second every time its switched off

Exhibit A- See above

Kramnik is right about the chess degenerates LOL!

@KenulL_76 said in #2:

Lichess offers compensation for lag. in ultra time is important so players switch their vpn on and off to get the compensation and win +1 second every time its switched off

I wonder if there's a way that lichess can spot lag switching
Perhaps by checking the strength of an internet connection the moment the network switch occurs.

@A_0123456 said in #4:

I wonder if there's a way that lichess can spot lag switching
Perhaps by checking the strength of an internet connection the moment the network switch occurs.

No, there is no way to reliably prove someone is lag switching. And it's easy to do.

This is (one reason) why lichess should implement proper timeseal-like lag compensation rather than the idiotic strategy they use now. This means reporting think-time from the client side rather than making error-prone guesses from the server side.

While it is true that timeseal-like solutions can be subverted as well, it isn't nearly so easy; and it would be particularly difficult for anyone using the mobile app. (Lag switching is as easily doable on mobile as it is on a desktop.)

But don't hold your breath. As far as I can tell, the devs simply don't get it.

@The_Great_MAGA_King said in #3:

Exhibit A- See above

Kramnik is right about the chess degenerates LOL!

Absolutely 100% correct!

@mrjbones said in #5:

While it is true that timeseal-like solutions can be subverted as well, it isn't nearly so easy; and it would be particularly difficult for anyone using the mobile app. (Lag switching is as easily doable on mobile as it is on a desktop.)

But don't hold your breath. As far as I can tell, the devs simply don't get it.

Finally, well said. I have been saying that the bullet games and hyper bullet games have changed for the worse. Everyone shoots the messenger, but in reality it is about making the games fair and balanced.

@mrjbones said in #5:

No, there is no way to reliably prove someone is lag switching. And it's easy to do.

This is (one reason) why lichess should implement proper timeseal-like lag compensation rather than the idiotic strategy they use now. This means reporting think-time from the client side rather than making error-prone guesses from the server side.

While it is true that timeseal-like solutions can be subverted as well, it isn't nearly so easy; and it would be particularly difficult for anyone using the mobile app. (Lag switching is as easily doable on mobile as it is on a desktop.)

But don't hold your breath. As far as I can tell, the devs simply don't get it.
Timeseal cheating requires no more than a small app manipulating your device's clock. This app has been written decades ago. Probably it would require some adaptions to current operating systems, but a few days after any of the big chess sites switches back to timeseal, these adaptions will be available.

But I doubt that mrjbones will get it.

@sheckley666 said in #8:

Timeseal cheating requires no more than a small app manipulating your device's clock. This app has been written decades ago. Probably it would require some adaptions to current operating systems, but a few days after any of the big chess sites switches back to timeseal, these adaptions will be available.

And? How difficult is is to measure a clients clock? Before, during and after a game. If an app can manipulate a clock then can that clock not be compared to another clock that is an independent variable?

@sheckley666 said in #8:

Timeseal cheating requires no more than a small app manipulating your device's clock. This app has been written decades ago.

Eh, no. You clearly don't get it. And you apparently weren't around and writing code back when timeseal was written and subsequently hacked. I was.

A separate app manipulating your system clock is not at all how it was done. That would be f'n difficult. You'd also need the chess client to communicate with that app telling it when to change your clock and by how much. And then your system clock would be all messed up for everything else that used it.

In the ICS/FICS days, timeseal was a separate program run on your PC (we didn't have smart phones then.) This was necessary because everyone used different third party clients to connect to chess servers. The exploit was a hack on the timeseal binary. Once it was hacked, cheaters only needed to install a hacked version rather than the real timeseal. There were at least a couple of those available. They all worked essentially the same way, by adding a randomized offset to the time in the timestamp calculation. Thus the encryption that timeseal used didn't matter because it was the altered values that were encrypted and sent to the server.

A timeseal like routine could simply be included in the lichess mobile app. For the iphone world, this would all but eliminate the danger of cheaters. Some determined devs might hack it for themselves, but distribution would be difficult. For the android world, distribution would be somewhat easier, but it would still take some dedication on the cheater's part. And there are other steps lichess could take to make it even more difficult.

As for the website, someone could potentially hack client side code with a browser extension... but lichess already disallows various browser extensions and their task would be no more difficult than it is to catch people using KB or one of the multiple premove extensions.

Whereas lag switchers can use an easy-to-write vpn connect/disconnect script and bind it to a keystroke... or, in a pinch, a loose ethernet cable will do the trick. Seriously.

Hope that helps you get it.