I've done silent drill routines. I'll give a rundown of how silent drill works.

In a normal routine the commands are called and when called, the platoon moves according to the command. In silent drill you have to remember when a command would be called. How does one do this? Counting steps is the magic secret. It takes a while for everyone to remember everything and it can make for some funny moments. You know you've counted wrong when you try to "flank left" and you bump into the guy to your left, then get bumped into by the guy behind you. Snowballing is a very accurate description of this situation. Here is an example of what might be going through your head during silent drill.

The numbers mark steps, the oblique is a formation change (left being the new direction of travel) the oblique will be started on your 11th step. All formation changes are started with the left foot. So:

Count: 1,2,3,4,5,6,7,8,9,10,Oblique left,1,2,3.......

Foot: L,R,L,..........................L..................R,L,R...

So the total of what you have to remember basically boils down to a list of steps, then the command which when written down looks as plain as this, "#steps, command, #steps, command, #steps." Once this list is memorized then all you have to do is count during the drill itself. That is, after you make sure your uniform is in PERFECT condition. How one looks is as important as how one looks doing.

That's pretty much all there is to silent drill, in theory at least. It is much more difficult in reality let me assure you. But what about all that rifle spinning? There are counts for those too, but that's another node.

One of my favorite commands for silent drill was a move called "mass chaos." Marching in standard formation (a rectangle) we would march X number of steps forward, then on the last step mass chaos would start. Everyone in the formation was given X number of steps and on the last step you had to land on a pre-designated spot, which would leave everyone back in formation. The effect was this, the platoon is walking along perfectly in step when all of a sudden everyone goes in completely different directions. Some people walking straight away from the formation some walking in circles, utter chaos. Then as quickly as it began all of a sudden BAM everyone is back in formation and marching forward again. Silent drill when done well is a truly amazing thing. Want to see the best? No this is not an opinion this is a fact, the best in the business of silent drill are the marines at 8th and I the D.C. post. Even the most perfectly choreographed ballet looks shoddy and sloppy compared to these machines.