The state gambling commission has heard a pitch from MGM Resorts International, the only applicant for the western Massachusetts resort casino license. MGM President Bill Hornbuckle said a revitalization of the city's downtown was central to the company's plans. While Sarno said the casino could be a ``game changer'' for Springfield. As the only western Massachusetts applicant, MGM is in prime position to be awarded by the commission one of the three regional casino licenses allowed under state law. The two companies competing for the sole eastern Massachusetts license, Wynn Resorts and Mohegan Resorts, made presentations to the commission on Wednesday.