It appears to give Arizona State an additional one- to two-point advantage per home game, beyond the normal homecourt advantage. The Curtain may even have played the pivotal role in the Sun Devils’ recent upset of their state rivals, the Arizona Wildcats.

The easiest way to see the effect is to compare visitors’ free-throw shooting percentage before and after the Curtain’s 2013 introduction. In each of the three seasons from 2010-11 to 2012-13, visitors missed 28 to 32 percent of their free throws. Last season, the Curtain’s first, the rate at which visitors missed free throws rose sharply, to 40 percent.

In the first 14 home games of this season — when the Curtain and its surprises have continued to appear — visitors have missed 36 percent of all free throws. If you didn’t know better, you might suspect that the size of the hoop had gotten smaller.