Earlier quoted context omitted.
This is a significant challenge for sure, at least with Ethereum there's no way around needing an external account (centralization) to feed data into the blockchain. However, I know of at least 1 promising project on Ethereum (Augur) that provides decentralized oracles, and you can trust these oracles due to some clever game theorish mechanics. The gist is randomized Reporters submit real-world information to the blo…
> Reporters purchased a cryptoasset to have this priviledge, and if a certain Reporter submits information in conflict with a majority of other reporters (e.g. they lied) then they lose a portion of their cryptoasset giving them incentive to play by the rules and get paid for it. To be precise: it gives them incentive to submit the same information as majority of other Reporters. This is a huge difference.
Now, imagine that team B somehow win the match. How can the system prevent the overwhelming majority of team A backers from submitting a fake result claiming that their team won? They will vastly outnumber the people backing team B, and also outnumber any of the casual observers who might also contribute to the results. So the market will get settled as if team A won, thanks to the 'wisdom of the crowd'. The minority backers will be robbed.