I found a graphic of the basic casting stroke on Gary Borger's Blog.
Gary Borger Blog Archive Casting From the Shoulder
It is the basic casting stroke that Gary Borger taught me and it is the basic cast that Jason Borger recommends in his book, Nature of Flycasting.
Examine the series of photos and illustrations below. Note that the casting stroke drawing of Gary Borger and the actual casting demo by Jason Borger are identical in their starting and stopping position.
If you look very closely at the photo below, Jason has modified his hand position a bit from Gary's. His hand is actually against his forehead.
It is Jason's method of illustrating that you must not take the hand back too far. By using his forehead as a stop, you cannot flop the rod backward in a "windshield wiper" stroke.
If you compare the casting stroke above to the stop motion photo below will see that this is the exact cast that the angler is making.
The stop motion photo comes from the Henry's Fork Lodge owned by Nelson Ishiyama. Nelson and I are college buddies, and he is the editor of Mel Krieger's book, The Essence of Flycasting
It is also the foundation cast that the Rajeff brothers use as their fishing casts. As a youth, Steve Rajeff was taught by Mel Krieger.
The Secret to an Easy Cast | The Henry's Fork Fly Fishing Lodge
Lou Lanwermeyer comments, "I was fascinated and discouraged. Could it be this simple? Why hadn’t I ever seen this before? How long would it take to forget all my other habits – some not all that good – to learn this new style?"
The answer is that it is that simple and it gets even simpler. The diagram below comes from a casting chart by Gary Borger. You hang the chart against the wall, and stand next to it so that you can follow the stroke path. It is the chart for a right handed caster. Turn your body to the left so that your right side faces the computer screen.
The stroke path is a simple triangle with the stroke on the diagonal, you begin with the rod at "C", lift your right hand to "A" with a hard stop. That is the back cast stroke. Then you pause. The forward cast is the stroke line from "A" to "B" with a hard stop at "B". The you lower the rod to "C" following the the fly line to the water.
Position "B" about half way between "A" and "C".
To false cast you tilt the stroke line so that it is more parallel to the ground.
The final part of the casting stroke is loop formation. If the rod tip truly follows a SLP (straight line path), at the stop, the fly line will hit the rod tip. So there needs to be a slight flick of the wrist just before the stop to move the rod tip out of way, below the path of the following fly line. Doug Swisher calls this wrist flick a "micro wrist". The greater the flick, the wider the loop. The following illustration from Jason's book illustrated the relationship between the flick and loop formation.