as far as game sales, madden 15 has two months on nba. the nba doesn't get popular until after dec and nba 2k14 stayed in the top 10 most of all last year.
nba 2k is going to be competing with fifas popularity very soon as they continue to add world basketball leagues from every country. there are so many dlc micro transaction options for commentary and league additions it is scary.
just imaging if they add chinese league and commentary charge a couple bucks for these dlc and league add ons to a nation of 1 billion... it will be like printing their own money.