There were leaked patents Activision had regarding matchmaking based on performance. It was an ineresting read, I don't remember the exact details to share here and there's no proof they are in MW but who knows with Activision. I've noticed when I have a game or two in a row with a great connection melting everyone on my way to nukes, the next few games my hit registration is off like I barely have any aim assist and my bullets miss the target. It ALWAYS happens, I'm sure there is something deep down they're doing to cripple you on purpose to give others a chance (catering to noobs). Hopefully this isn't the case with the new Black Ops.