Hidden has the problem of having elite players. I was playing on a server one time, and eventually we had this one guy come on.
He was an expert, no other way of describing it. Within moments he had found and shot the prvious hidden player, and then proceeded to unleash a reign of terror upon the rest of us. He'd jump over our heads, throw crates at us, and generally kill the entire team of IRIS members in the space of a few minutes. He didn't throw a single pipe bomb, and pigsticking was disabled for the server.
Then someone else came on. He immediately shot off in some direction alone, while the rest of the team (including me) tried to watch each others' backs and try not to die.
Then we heard shooting, and something smashed. Then, couple seconds later, we receive the message that so-and-so has killed the hidden.
At first we cheered, but our smiles turned to grimaces of horror. This dude was just as evil as the last guy, and he killed anyone who got in his way. But the thing was, he wasn't better than the guy he had just bumped out of the hidden spot. A few moments later, we receive another message about the hidden getting killed. Well, back to dude #1.
Eventually, things fell into a rhythm. Guy #1 would run out and find the hidden, guy #2. Then guy #1 would kill guy #2, ending the round. Next round, the roles were reversed.
Everybody else just stayed in the elevator. There were several rounds in a row where none of the "lessers" fired a single bullet. At anything.
Eventually, we just started wandering off and goofing around on the level while the two pros duked it out, ending the matches in what was sometimes a matter of seconds.