I apologize for not having time to get back to some of the other responses. I have been very busy in the fluted point factory.
The title should read: "Logical Reason for Employing Controlled Overshot, in Opposite Edge Thinning"
(Disclaimer: The purpose of this thread is not to show a "how to" tutorial, on how to produce overshots. If a person reads the text that accompanies the photos, the purpose will be seen to follow the title. Also, Zuma probably would not want this information in his other thread. For this reason it is not included in his other thread, on overshot. Also, this thread does not raise the question as to whether controlled overshot was employed, by Clovis knappers. Thus, it is not in one of the previous threads. This thread simply shows the logic in employing controlled overshot, as a means of thinning opposite edges, when opposite edges are thick, and not directly unworkable. In essence, I want to show a logical reason as to why a knapper may have had the intent to use an overshot/coast-to-coast flaking technology. This thread is about a hypothetical reason for intent.)
Okay, here is my edge. How should I thin it? The stone is raw, and acutely hard. If I try to use a hammerstone, it would be very hard to break. Plus, hammerstone percussion could produce internal shatter, in the square edges. If I try to use a baton, it might not do anything, because the stone is profanely hard, and in a raw state. If I try to use a pressure flaker, I cannot generate enough strength to remove a flake. So, how am I going to thin it?
Here is my solution to the problem:
I am going to used tine-based flaking to work from the thinner opposite edge, so as to remove flakes that are designed to thicken as they travel. By doing this, I can remove thicker flakes, while working off of the thinner edge, which will effectually thin the thicker opposite edge.
Here is one such flake. The initiation is quite thin, but the far edge of the removal is thicker:
Here is the flake scar, after removal:
Now, the "bad" side is a little thinner:
Here is the thin edge, where I am shooting flakes from:
Here is the thick edge, that is getting thinner, from far side removals:
Now, after some very unusual prep work, I take a removal off the thick edge, heading towards the thin edge:
Now, I will take off another removal from the thick edge, heading towards the thin edge. Here is the leftover delta:
Here is my thick edge, after the removal of the delta:
Now, I am going to take off another removal heading from the thick edge, back to the thin edge:
(As a matter of intentionality, the preparations and modifications employed in preparing for the previous outrepasse flake, were not the same as the preparations and modifications employed, in preparing for the previous multiple coast to coast flakes. For some, knowing this could be a prerequisite needed prior to considering this subject, from the standpoint of "intent".)
So, as I have shown here, the flaking technology that produces overshot flaking, coast to coast flaking, and regular flaking, can be used to thin opposite edges, when the far side is too rough, and thick, to work. Once the thicker edge has been thinned enough, then it can be worked off of, too.
Here is another example. The opposite edge was too thick, and irregular, to pressure flake. Since the stone is raw, and finely grained (raw agatized coral?), it would not have responded well to hammerstone percussion.
So, I used tine-based flaking, to remove an outrepasse, from the far side, while taking off the thick, opposite edge in the process (middle segment of the flake is missing, probably due to shatter).
Again, this thread is not about whether or not Clovis knappers intentionally employed outrepasse flaking. This thread is about the logical reason for employing late stage, tine-based outrepasse flaking, when distant surfaces - and sometimes even opposite edges - are overly thick, while the stone is raw, and not very susceptible to other methods of flintknapping.
P.S. A researcher has responded to this post, and pointed out a parallel to "PSE" paleo end scraper blanks, in terms of generating flakes that are designed to thicken, as they approach the opposite edge, with the greatest thickness involving the curl around the far edge.