Will the "quiz game" facility allow to implement sport bets? To avoid a massive overhead on delegates, you should rely on oracle scripts stored on the block chain that would check the results of sport events on multiple bookmaker sites, reconciliate the results to detect inconsistencies, and input the resulst in the blockchain as signed messages. The role of delegates would then be to audit the oracles code, make sure they are reliable, and run them. Codius could be a good plateform for that.