Sparring should always benefit the least experienced fighter. Whoever is running the gym should watch so that somebody doesn't go in the ring and get the sh** beat out of him. I've spent a lot of years in karate dojos and boxing gyms. I can't tell you how many times I went in the ring with some egomaniac a**clown who was just looking to give someone a beating to show everyone how great he was. Be wary of these guys. The guy who ran the first dojo I belonged to used to watch the sparring. If someone was going too heavy he would take the other fighter's place and beat the crap out of the aggressor. Most of the time they left and never came back.