This is a very basic primer for team Tactics. Hopefully I
will be able to write more on the subject in the near future.
Team play is largely about strategy, this is in a major way knowing the strengths and weakness of your team. While good communication and effective cover certainly play a part of this, these topics have been talked about elsewhere so I will not touch on these subjects here. Indeed a chain is only as strong as its weakest link, should one player be beaten badly the entire team will suffer. A team has to attempt to prevent its players from having to work within their weakness and instead help them work within their strengths. A good quick trigger who is a poor dueler should obviously not be made to duel. Simply by having your good duelers keeping track of where you poorest dueler is often aids the team incredibly.
A single player is in his weakest position, though stealth advantages are definitely there for the solo player. While it is indeed the teams responsibility to watch each other and prevent team ups against their teammates it is equally the responsibility of a ghost to know where the rest of his team is, should he find himself/herself in a situation he/she cannot handle. Equally so teaming up against ones opponents has definite advantages. If two players are fighting against one, it is often easiest to have one player simply block (the one being shot at) while the other hits their opponent.
Knowing your opponents strengths can also greatly aid your team. The best player may need to be teamed against, particularly if he/she are on a team of comparatively unskilled players. Equally so one can put your strongest dueler against the weakest dueler on the other team. This may result in putting the worst player so far into negatives that it doesn't really matter how the rest of the team did.
Having a strategy, and sticking to it, is most of the difference between a good team and a bad team.