The centerpiece of the proposal to the N.B.A. is the Mandalay Bay resort, which has 4,700 rooms at three connected hotels at the southern end of the Las Vegas Strip: the Mandalay Bay, the Four Seasons and the Delano. They are also connected by an enclosed walkway to the Luxor hotel, which is where MGM service staff such as housekeepers and caterers would live. As many as 24 basketball courts could be built at the convention center at Mandalay Bay, which hosts the Aces of the W.N.B.A. Five would be used to telecast games, while the others would be for practice. MGM also proposed getting access to the Thomas & Mack Center, an arena on the campus of the University of Nevada, Las Vegas, that hosts the N.B.A.’s annual summer league.