Sep 13, 2015; Arlington, TX, USA; Dallas Cowboys running back Darren McFadden (20) carries the ball against the New York Giants at AT&T Stadium. The Cowboys won 27-26. Mandatory Credit: Tim Heitman-USA TODAY Sports

The NFL’s Dallas Cowboys are the world’s most valuable sports franchise, according to a Forbes poll released on Monday that said new broadcasting deals helped boost the league’s average team value by 38 percent from last year.

The Cowboys, who unseated Spanish soccer club Real Ma