I showed you the gaping chasm at the line of scrimmage for Murray to run through with 77 as the lead, on a draw play in the first quarter of the Rams game. That was an example of a play executed exceedingly well.
Now I want to show you the same play with completely opposite execution and results. I showed you the good version, now here's the bad.
In the second quarter on 2nd and 17, the Cowboys ran the exact same play, except from shotgun, and it got completely blown up. It was probably their worst offensive play of the game, and narrowly avoided disaster.
The formation at the line is exactly the same, with Dez left and Witten, Miles and TWill out right. The only difference is that instead of Romo under center with Murray deep back, it's shotgun formation.
To copy what I said about the version that worked, "To this point they are completely selling a pass. Oline are high hats, in pass pro sets, defending the pocket instead of blocking downhill. Romo is looking out toward his 3-receiver side. Murray is looking like he's scanning for blitzers." Except for where Romo and Murray start, it's the exact same play.
Now Murray has the ball. But things have already gone badly awry. Instead of ejecting his man upfield and out of the play, Tyron doesn't follow through on his block and Quinn just turns the corner and heads directly towards Murray, who hasn't even taken a step yet. Meanwhile, instead of throwing his man to the turf, Leary has himself been thrown down and is sprawled out, leaving his man standing in Murray's path.
Now Murray, still four yards in the backfield and having taken only one step, has one defender lining him up for a hit from the front while another strips the ball from behind. Tyron hasn't even turned around and has no idea what is happening behind him. Leary is just regaining his feet. The play is totally doomed, Murray has the ball knocked out by Quinn, and only his managing to get it back at the bottom of the pile saves the play from being an utter disaster.
The same play. Two completely different results. We won the coaching chess match and the execution on almost every play in this game. But on this particular play, the Rams' defenders had seen the same formation earlier and were ready for it, and the blockers who were supposed to open the lane and lead the way completely failed to execute.
It's all about calling the right play at the right time, staying one step ahead of your opponent's adjustments, and then 11 guys actually running the play the way it's designed and not getting beat. The same play can succeed in spectacular fashion once and then fail in equally spectacular fashion in the same game.