
12. Jason Garrett
The Jason Garrett era was the second-longest head coaching reign in Cowboys’ history. However, they don’t have much to show for it. Tactically rigid, anything that went against his ideas threw him into disarray. For example, they went 1-11 in 12 games without Tony Romo in 2015. He proved to be second-best in the playoffs over the next couple of seasons before entering 2018 with no wide receivers.

Over his time in charge, Dallas lost crucial games which they should have won. Garrett had one of the worst kickers in football in Brett Maher. However, he didn’t cut him until it was too late. He wasted so much talent and made some inexplicable calls. In sum, Jerry Jones is responsible for a lost decade of Cowboys’ football by allowing Garrett to lead the franchise into football’s purgatory.