Query Caching

The average latency of the Vars and Users query types differs drastically, by 186 ms (89 ms vs 274 ms). Both queries take the same path to the same machine, so with a gap that large there's a good chance the server's network is answering Vars out of its own cache instead of passing it through to the game server. This is often used as a mitigation tactic for low-throughput (D)DoS attacks, and if that is what's happening here, the side effect is that the latency from the in-game server browser can be inaccurate — it measures the edge server you are routed through (usually the one closest to you), which is why the browser often shows a lower ping than you actually get in-game.

Anycast routing adds to this: the same IP address is announced from many locations at once, so your packets land on whichever edge is nearest to you rather than on the machine the game server actually runs on — the ping you measure is the distance to that edge, not to the server.