On my CS:S server, we kick anyone with 200+ ping. Now, in a decent game with good netcode, a 56k player can play just fine, or play very bad, it's up to an admin to watch and see. Pings up to 250, even 300, might be totally playable. However, dialup never hits 56k speeds, and often goes much lower. It also can have terrible packet loss, which will cause serious teleporting. Latency could just be nasty and you can find people with upwards of 800 pings! I kick 200+ pings just because CS:S has crappy netcode, and they will have an easier time killing me than me killing them. In the league we are in, a match can only take place on a server where both teams average pings are within like 50 of each other.