And now for something completely different, here is Matt Yglesias on three-point shooting in the NBA:
In general, there’s not enough three point shooting happening in the NBA. In the 2008-2009 NBA season the average possession resulted in 1.083 points. The league average on three point shooting, meanwhile, was .367 meaning that the expected value of a three point attempt was 1.101 points. Better than average. Indeed, last year only four teams scored at a more efficient rate than 1.101 points per possession.
My takeway from this is a little different: it's astonishing how close these two averages are. If you assume that players generally attempt the best possible threes, then additional attempts are going to have a poorer success rate. Probably much poorer, since I imagine that effectiveness falls off exponentially with distance and coverage. In other words, if NBA players attempted even 1% more threes, the expected value of triples would probably fall below the average possession.
That's no big surprise, I suppose. Professional basketball players, it turns out, have an extremely precise sense of how effective various plays are. Still, the fact that they take threes at something like 99+% of the ideal rate is pretty remarkable.