I would neither like when my son were to participate in such a competition as a slapper nor would I like if he was standing around screaming like a cheerleader when his favorite slapper humiliates his opponent. That is just stupid. I don't like boxing either because I think that our brain is so valuable, it allows us to do so many things, feel so many things and so on. Why get it slapped permanently until it might take damage and stop working accurately or maybe even lead to death? That is just not my thing I guess.
Every professional sport causes serious injuries to athletes. Soccer players often have problems with their knees and feet, jumpers have problems with their spine, boxers have problems with their head.
To avoid serious injuries, you can practice boxing for 2-3 years. After that, you can just keep in shape. Such training makes a person very tough and strong in spirit.