Lag compensation

Lag compensation tries to separate the time a player spent thinking from the time the move message spent traveling across the network. When the server receives a move, it may estimate part of that delay and restore it to the clock according to the platform's technical rules.

The mechanism does not grant free thinking time. It only corrects, within limits, a portion attributed to communication. It also cannot know perfectly what happened on the player's device. A pause before clicking, a local animation, move confirmation, or an overloaded computer may fall outside the correction.

Platforms limit compensation to preserve fairness and reduce abuse. They may treat sustained delay, a single spike, and extremely fast clock settings differently. They may also consider how much time has already been compensated. Two moves with the same visible lag therefore need not receive exactly the same adjustment.

Compensation does not guarantee protection from a disconnection. If the link fails completely, the server may receive no move from which to measure and correct transmission time. Site or tournament rules determine what happens to the clock and result in that case.