Each year, the National Basketball Association (NBA) has a fixed number of games among a fixed number of teams.  This means each season is a zero sum game.  There will be equal number of wins and losses.  Those wins and losses might fall on different teams each season, but still they are equal to the number of scheduled games.  

Like other things that are fixed in this scenario, we have to optimize within those constraints or work around them.  

This creative thinking lead to the development of fantasy leagues.  When you pick players from multiple franchises and pit them statistically, you aren’t as limited to the same number of games or teams.  In fact, a fan can have multiple teams, each created with different players and played with different strategies.