From a Buddhist's perspective, is it wrong to watch such sports on television for example? Of course, I'm talking as a lay person. Monks have a completely different approach regarding entertainment.
Does watching it create any bad Kamma?
In one instance a head of a group of actors asked from Buddha if his profession is a good one and whether he could go to heaven because he provides entertainment. Buddha refused to answer this question three times. But when he insisted on, Buddha's answer was,
Any beings who are not devoid of passion to begin with, who are bound by the bond of passion, focus with even more passion on things inspiring passion presented by an actor on stage in the midst of a festival. Any beings who are not devoid of aversion to begin with, who are bound by the bond of aversion, focus with even more aversion on things inspiring aversion presented by an actor on stage in the midst of a festival. Any beings who are not devoid of delusion to begin with, who are bound by the bond of delusion, focus with even more delusion on things inspiring delusion presented by an actor on stage in the midst of a festival. Thus the actor — himself intoxicated & heedless, having made others intoxicated & heedless — with the breakup of the body, after death, is reborn in what is called the hell of laughter. But if he holds such a view as this: 'When an actor on the stage, in the midst of a festival, makes people laugh & gives them delight with his imitation of reality, then with the breakup of the body, after death, he is reborn in the company of the laughing devas,' that is his wrong view. Now, there are two destinations for a person with wrong view, I tell you: either hell or the animal womb.
So I think this applies to such sports as well because they are not devoid of passion, aversion and delusion. So technically, any action or intention with desire, anger and delusion should create bad karma.
Does it create bad Kamma?
It can! Watching the news, dramas, commercials, musical shows etc. can create bad Kamma. Seeing the no signal screen can create bad Kamma. Doing school work can create bad Kamma. Eating an ice-cream can create bad Kamma. Drinking water can create bad Kamma. Smelling a flower can create bad Karma. Scratching your head can create bad Kamma. Stretching your arms can create bad Kamma. Even if you sit in the dark and do nothing, you can still be creating bad Kamma. It depends on whether you have Samma Sati or not. Whatever you do can create bad Karma as long as your thoughts are defiled with craving, aversion and ignorance.
Is it wrong to watch sports entertainment?
Only if you take the eight precepts. MMA, Judo, Boxing etc. fall under the 7th precept.
Nacca-gita-vadita-visukkadassana mala-gandha-vilepana-dharana-mandana-vibhusanathana veramani sikkhapadam samadiyami - I undertake the precept to refrain from dancing, singing, music, going to see entertainments, wearing garlands, using perfumes, and beautifying the body with cosmetics.
So it will be wrong to watch them on Poya days when you take the eight precepts.
Can it still create Karma even if you don't take the precepts? Yes.
"Wrong" is highly subjective. I dont see how simply seeing something going on in front of you is inherently "wrong"... It would be detrimental to an attempt to practice the 8 precepts strictly if it is viewed as entertainment and is certainly not necessary for practice. Kammicly it could attach your mind (if you are entertained) to aspects of reality giving them a propensity to bring about a possible good or bad situation really. speculation on that is dubious at best.