Those who think McVay forgot how to coach need to notice that in the NFL it all begins with the running game. If you can't run, your odds of winning are pretty low.
The Rams lost RBs 1 and 2 in the same game, and then for an extended period of time. Their best WR is gimpy and clearly not all the way back. Their QB has less control on his passing due to a thumb injury. This all leads to an offense that is herky-jerky and can't sustain drives no matter what plays are called.
But now, the Rams have a pretty darn good 1-2 punch at RB with Williams and Freeman. You can see why McVay has been a Williams cheer leader since the day they drafted him. And, finally getting enough carries, Freeman has gotten in synch with his Oline. And the Oline is getting in synch with each other.
With the running game going, McVay can call the same game but with far better results. It also opens up the passing game so the windows are a little larger.
But one other factor: Stafford really spread the ball around and took the check down options that were very successful because Williams is such a good screen player.
I also like that they took some of blocking load off of Higbee so that he was fresher to run routes, and they involved him more early in the progressions.