Anything that interests you?
I assume you should be writing as to why boxing interests you? Thats up to you
Not sure if you're in a school or college, or whatever, but make it academically interesting, maybe something along the lines of:
Context of boxing (history, and what roles it plays in society)
Links between history and now (Corruption, how its the same or changed, sanctioning bodies, titles, type of people who box)
The effects of globalisation (how this has changed the boxing scene, a good thing to write here is perhaps the olympics especially London 2012, rise of Europe at heavyweight, female boxing, Manny Pacquiao, China suddenly appearing in the mix recently)
Future of the sport (how you see it playing out)
Conclusion - why boxing is and should be a key sport.
My outlook on the sport tends to centre around the idea that boxing is much more professional now, its purpose in society is no longer solely to get kids off the street, but also caters towards people who just have a keen interest too. Corruption is still there though still unproven, its the pink elephant in the room. Boxing is also not fan-friendly - it caters to the needs of the people making money, not its fans - a good argument distinguishing it from other sports. Globalisation has made a massive change to boxing. The US is slowly losing its status as the boxing nation of the world because of the nature of the world today.
Not sure if this is what you wanted, but I tried anyway