a few things happen in pvp
1. you have a couple guys who are great on mics running everyone. this usually means the top 2 guys have a ton of kills and everyone else goes negative. have seen this happen countless times
2. the lag is so bad you can dump 2 mags in someone and they don't die. if this is a player intentionally lagging or bungies servers i have no idea
3. many maps are CQB which means shotgun fest
4. you get a decent server and have some good games. i have literally went 2.0+kd and .3kd with the exact same players all depending on the connection and i don't even play pvp often. it did however show me why people leave games so much. if you actually care about your pvp stats you're at a MAJOR disadvantage if you have a crap connection and running behind the actual game