> The only X factor here is the impact of the client lieing about its latency to the server, perhaps that could have an impact, not sure.
on lichess it does have an impact. lichess has a thing they call lag compensation where the server can add time to a player's clock after the server receives their move.
The goal is to make it fair for someone with high lag playing someone with low lag.
I don't know the exact cheating method used. I'll have a guess, though. What if someone spent a few seconds looking at the board before making their move, and then adding (edit: oops, subtracting) a few seconds to their clock in their response packet. The server would see the client made their move instantly based on the time in the response packet, but it took a few seconds for the server to receive the packet. i.e. lag. So it might add time to compensate for the perceived lag.
Lag compensation cheating is a frequent topic on the lichess forums.
