No you don't. Football players always celebrate after a big hit. Baseball players celebrate after a big play, even if someone got hurt in the process. Basketball players celebrate after a big dunk, even if someone got injured in the process. Soccer players celebrate after a score, even if it means someone got injured. It happens in every sport, don't pretend it doesn't.
"Do you think man will ever walk on the sun? -Ali G
Retired pro-MMA fighter here, as a women's strawweight. I've played other sports, but to be honest, I'm not so good at the more technical and finesse aspects of sports. I played football as a receiver, returner and sometimes defensive back, but I was always an arm/chest catcher. I'm terrible at baseball and soccer. Some people really excel at the violent aspects of some sports, and excel at the violence in purely violent sports. I was a Judo player before I was in MMA. A lot of people are high school and college wrestlers. A lot have played muay thai or kyokushin.
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The main cause of that, ironically, is less protection. You're more likely to go down and out, earlier in a fight, and sustain less damage over the course of a fight. Fighters also have the benefit of referees being ready to call TKOs at the moment someone's not able to adequately defend themselves, instead of letting a guy just get pummeled into the ropes, or knocked down over and over again in boxing.
Yes you can... There are countless fighters who have class (Couture, Severn, Smith, St. Pierre, Shamrockx2, any Gracie, etc.). MMA is an art and/or a sport. It's much more technical than you think... More technical than football or baseball. There are always guys who want to be "bad boys" and since you don't know anything about martial arts, that's all you see in the news.
It actually doesn't bring in much money unless you're Conor McGregor, Brock Lesnar, Jon Jones, Ronda Rousey, Holly Holm, or Miesha Tate. And all those people I just named? Half of them make a lot less in one year than any third string professional NBA or NFL athlete. Ronda's first UFC opponent only made $10k per fight (even though it was a title fight), and keep in mind a fighter will typically compete only three or four times per year. Oh, and in every UFC contract there's a clause where you give the UFC complete and total rights to your likeness for all of eternity, so if you ever want to print shirts or allow a game to use your likeness, even if you're not in UFC anymore, they won't let you. UFC is pretty scummy to their fighters, but most of them don't fight back because they're passionate about fighting. If it was about the money, all of them would be doing "real" sports instead (if they had the talent for it).
That looked painful as fuck.
There's some evidence that rather than knockout events doing the damage the stuff that you can stand through in boxing has a greater cumulative effect. Getting sparked and passing out is a survival trait after all . However being jabbed in the face by a big padded clown glove and having your brain bounce around in its cage isn't probably that healthy. It's a shit load of fun though!
I was looking at the one guy and I thought, look at those skinny legs. Apparently it didn't stop him from kneeing in his oppenents skull.
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"This will be a fight against overwhelming odds from which survival cannot be expected. We will do what damage we can."
-- Capt. Copeland