> ...although some prefer to play using timenudge...
Timenudge is not cheating by any stretch. It's been a long time since I looked into Quake Live's netcode. Someone here will probably know about this, so if you know more please correct me.
The server that you're playing on has a fixed framerate (server 'tick rate'), and periodically sends packets to connected clients containing the current gamestate (player locations, scores, etc). Your client deals with the latency involved by interpolating between the last two received packets. This means that what you're seeing is always (your_ping + server_tick_rate)ms behind 'reality'. Quake Live uses 'backwards reconciliation' on the server. When you fire a hitscan weapon the server looks at the server frame (your_ping)ms back in time to see if you hit something. These two reasons are why you might have experienced being railed around corners by high ping players. You were under their crosshair on their screen, but on yours you're in the clear.
What timenudge does is adjust the client's interpolation period. A server_tick_rate of 40fps makes for a delay between packets of 25ms. Since the client is interpolating between the last two received packets, your client is working with what is effectively an artificial 25ms delay. A timenudge of -20 tells your client to reduce that interpolation frame, at the cost of some accuracy. It's not cheating. It doesn't really give people any practical advantage at all unless you've got a totally obscene ping. If anything it'll exacerbate the effects of other players warping (caused by the server not receiving their client packets in the right order, or at all).
Timenudge is not cheating by any stretch. It's been a long time since I looked into Quake Live's netcode. Someone here will probably know about this, so if you know more please correct me.
The server that you're playing on has a fixed framerate (server 'tick rate'), and periodically sends packets to connected clients containing the current gamestate (player locations, scores, etc). Your client deals with the latency involved by interpolating between the last two received packets. This means that what you're seeing is always (your_ping + server_tick_rate)ms behind 'reality'. Quake Live uses 'backwards reconciliation' on the server. When you fire a hitscan weapon the server looks at the server frame (your_ping)ms back in time to see if you hit something. These two reasons are why you might have experienced being railed around corners by high ping players. You were under their crosshair on their screen, but on yours you're in the clear.
What timenudge does is adjust the client's interpolation period. A server_tick_rate of 40fps makes for a delay between packets of 25ms. Since the client is interpolating between the last two received packets, your client is working with what is effectively an artificial 25ms delay. A timenudge of -20 tells your client to reduce that interpolation frame, at the cost of some accuracy. It's not cheating. It doesn't really give people any practical advantage at all unless you've got a totally obscene ping. If anything it'll exacerbate the effects of other players warping (caused by the server not receiving their client packets in the right order, or at all).
There's some good information on how this system works here: https://web.archive.org/web/20160302024647/https://www.ra.is...