Mavs moving to Valley View and Rangers moving up?

SportsDay Insiders Kevin Sherrington, Evan Grant and Brad Townsend discuss the Mavs pending move to the old Valley View site, and with the Stars' accompanying move to Plano, the prospects of an urban core without an NBA or NHL team for the first time in nearly a half-century. Brad lays out the process that led to it and how it's probably the best move for the Mavs, if not the city. Evan says the…