Interesting, something new? I never have seen such betting platform. Good luck.
What exactly does decentralised means? Your platform is being controlled by you. Which means it is a centralized sports book.
You can create any event, imagine a match going on between Real Madrid vs Barcelona. You can create an event like Real Madrid to score 3 or Benzema to get a hat-trick (not possible though

) etc and when players bet on your event, you can get money from the bookie. This is really a great idea. I will wait for some feedback and later give it a try.