At the recent MIT Sloan Sports Analytics Conference, Mavs owner Mark Cuban opined: "There's not 10 players on the court, there's 13. And three of them determine about 80 percent of what happens out there."

The clear implication: understanding the impact that the referees have on the average game is crucial to truly understanding the game itself.

One of the attendees took Cuban up on his challenge and attempted to create an efficiency rating system for referees that quantifies their impact on offense and defense, adjusting for home court advantage. The results -- and full  Google spreadsheets -- are published at The Basketball Geek.

Personally, I hope never to be involved in a league so competitive that this sort of information would be useful... I just don't have that sort of time. But I can absolutely see where this sort of analysis would come in handy when doing player evaluations.

Or playing over-under lines.

(Hat tip: Henry Abbott at TrueHoop.)