Usually a guy who is hitting on a particular girl, but the inverse could also apply. Occasionally used for someone who is generally amusing at a social outing.
Derived from sports such as Rugby, Football, Basketball, where the camera tracks one particular player on the team, normally the play maker.
2. Tom: Hey Tim are you going to make a move on Kate tonight?
Tim: Yeah, but I've got player cam on Jack, it could be a bit of a dog fight I want to make sure I can suss out the competition.