You are given a data set of NFL matches, where each match has a pair of teams and you know which team won, by how many points (point spread), and also whether the winning team was the home team, as well as the stats of the team up to that game. You are asked to design a predictive model that will tell you which team will win in any future matchup. Is this a supervised or unsupervised learning problem? Explain briefly what sort of model you might use.