I think you also need to factor in the cities' populations imho. NY and Chicago have big populations so they have more fans attending their games despite the teams disappointing, Dallas as a city doesn't even rank top 10 on the population list but the metropolis of DFW has the 2nd largest population of this country, only behind the big NY metro. The attendance-population ratio can reflect the popularity of basketball in a city better than the absolute numbers themselves do imho, in which sense the Rockets have the tiest fan base. That city has the 3rd largest population of this nation, and a team that looks stacked and is supposed to contend, yet it only ranks 13rd on that list.