The N.B.A. has crowned a champion in each of its 73 previous seasons and wants to avoid the sort of unappealing, unresolved conclusion to a season that Major League Baseball endured in 1994, when a labor impasse halted play in August. League officials want this even if it means returning from a first-of-its-kind extended delay to play in empty arenas and serving up the type of raggedy product that could well result from a lengthy hiatus.