Ok, if I ask who boosts kdr, more or less 95% peoples are gonna say, no I'm not a booster, now lets do a reality check.

1> Are you used to reject 'go' of a better player/class than you?

2> Do you love to throw 'go' to an weaker player/class.

3> Do you find or make weaker friends to fight with em.

4> Do you team, hunt even unknown players, peoples say him a rusher/teamer/bad guy

5> You quit ffa/ctf, if you see stronger opponent team.

6> so on....

If the answer is yes of these/similar questions, then I'm afraid that, yes you're a booster, who sneak to groom and show off their kd through their whole pvp life (sometime).