Have you tried running your connector in the WDC Simulator? If not I would highly recommend it for development. It'll let you use web dev debugging tools to find issues.
I ran your code through the simulator and received this error:
XMLHttpRequest cannot load http://stats.nba.com/stats/leagueleaders?LeagueID=00&PerMode=PerGame&Scope=S&Season=All+Time&SeasonType=Regular+Season&StatCategory=PTS. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8888' is therefore not allowed access.
The good news is this is a solvable problem, check out some options for dealing with CORS in the docs.
Hope that helps,