Will it ever be possible to build a supercomputer?

Perhaps. It would be mive, planet-sized, and would have to have enough processing power to take into account the trillions of variables that are needed to predict the potential outcomes. It would need to be asked a certain question, more like "What will be the outcome of arsenal's next game" rather than "what's going to happen next week". It could look at things for the first question: Condition of the players, where the match is being held, etc. But for the second question, there is no way for it to predict the MOST LIKELY outcome.