Life might imitate arts but not sports. I love sport karate and I have done several karate and kung fu tournaments, and even won a few sparring competitions. But I also find it limiting. In a real self defense situtation there is no referee to stop the fight if someone goes outside bounds (there are no specific bounds to begin with), there are no gloves, cup and other protective gear, there are no time limit rounds. For us kung fu guys, a lot of hand techniques (eagle claw, chin na, dragon claw, phoenix eye punch, monkey hook, etc) cannot be use for the simple fact you are wearing boxing gloves! And don't get me started on that stupid rule you cannot kick someone while standing in one leg. Yeah, let me try that in a real fight. And some tournaments do not allow sweeps. Also, in a real self defense situation, no one stops the fight after "scoring a point".
Having say all that, I can see Alcatraz's point. Some elements of fighting can be enhanced by sport sparring. For example, distance, speed, timing, eye-hand coordination, supression of fear, knowing how to take a hit, control, stamina (most fights come down in tournaments to who have more stamina left after three rounds), etc. Any more opinions?