AT&T, T-Mobile and Verizon duke it out in TV ads over network performance — which one is telling the truth?

You can’t turn on your TV these days without clapping eyes on an actor touting the merits of one of the Big Three U.S. phone carriers. And in each one, the actor looks right into the camera to tell you the wireless carrier they’re representing has the best network.

The latest instance features Luke Wilson strolling around a wind-swept prairie and declaring AT&T to be the phone network to beat. This ad echoes a T-Mobile spot that debuted a few months earlier, in which Billy Bob Thornton strolls around a…