I'd like to say that fake errors can be pretty fun, like showing a side block to force your ennemy to attack you, and then chamber him, or to help an ally getting an easy kill. Crouching is also pretty fun and, against good players, pretty effective. There is always a fool trying to stab / kick stab a crouched one, then you just need to do a side step when the ennemy kicks, and give him what he tried to give you
However, I agree with Vikestad and Vorlen, but not entirely. A good groupfighter isn't a man who leaves his teammates behind and get kills, however there are points to understand, if the ally does shit, like rushing in an ennemy group, or not retreating against too much ennemies, or, just if he get in a situation he can't win, it's sometime necessary to leave an ally to save others. Also take care about the fact that a dead ennemy is an ennemy who can't kill your allies or, even, who can't kill you, by back or not
There must be both types of players in a team, the one holding the ennemies, playing defensive and doing their job, and the ones playing offensive, attacking by behind, being ninjas, and moving along the battlefield. If there are only holders they will be outnumbered, and if there are only ninjas there will be no teamplay.
Also, a group of 2-3 great players CAN hold a 8 terrible players team. Of course, they can't hold a normal 8 guys team, playing together and doing up/down attacks and good blocks. However, I already fought against groups of 6/8 with a friend or alone, and luck or not, I won some. The fact is that sometime players with a huge outnumber will try to have the kill at all cost, means teamkills, bad strikes, opportunities, a melee can be changed in three seconds. As an example, during the last Nation Cup against NL, I had a lot of guys on me, they all attacked, they teamhit /teamkilled themselves, and I just had to finish the survivors. (And I got killed by the last one
)
However, I agree with the fact that a player who always runs, even with good allies, with the single goal to get easy kills, even if his team get massacred, is pretty useless. But there are some situations where running is better than holding.