I’m going to bore you guys with some math. Obviously these percentages aren’t perfect but I think they are close enough and not biased one way or another.
If you run the ball:
33% of the time you get a first down outright
33% of the time you set up 4th and short, which you go for and convert 80% of the time
33% of the time you get stuffed / minimal gain and kick the FG
So you win outright 60% of the time (33% + 0.8*33%).
Now let’s say Seattle wins 33% of the time when you don’t win outright. I think this is generous since they have to either go 75 yards in 1 min with no timeouts, or get maybe 65 yards to tie with a FG, then win in OT. Still, let’s give them 33%.
So cowboys win 86% of the time doing it this way (60% + .66*40%).
Now the scenario from today. Throw the ball in the end zone, going for the win.
It probably converts 33% of the time. So you win outright that 33%. Now let’s give Seattle a 45% chance to go down the field and win the game. Keep in mind they have 40 more seconds this way, so an extra 12% is perfectly reasonable.
Seattle wins 30% of the time (0.45*66%). Dallas wins 70%. This is all being generous to the decision made tonight (with the numbers).
So yea, just run the ball.