Man, this thread has exploded. I see we're back on the overshot topic again 
Let me reiterate (some of) what I've said in the past; there are different types of overshots. The one's I would call a 'mistake' would be the plunging/taking a big bite off the opposite edge (key word being big). The coast to coast flakes are desirable as they feather out just to the opposite edge. (I think I have the terminology correct from the huge PP thread on this topic. I've been meaning to revisit that thread). Then there are blending flakes from the opposite edge toward the center, and if blended well look like overshots.
I think even Zuma would agree that a lot of Clovis bifaces, etc. exhibit long/bold percussion (whether indirect or not) scars. Some other/more recent cultures did too but not in the same way. Yes, I did work in a lithics lab during college and no, that does not make me an expert.
"That being said, if we are discussing hammerstone tech, I believe that most all overshots are accidental. If we are discussing billet tech, I think that overshots is difficult to achieve - AS NOTED BY BRADLEY. If we are discussing tine-based "pitching tool" tech, I think that regular flaking, coast to coast flaking, and overshot, is all fairly easy to achieve."
I have to agree w/ most of this. I've been studying bison horn/indirect for a few months and have been getting fairly consistent coast to coast flakes. I'm finding, as Marty told me, the correct inward and support, not to mention platform prep, will achieve longer flakes.
Turbo,
Between regular flaking, coast to coast flaking, and overshot flaking, I realized that there are actually two types of flaking, that result in opposite edge removals.
One kind of flaking happens when the break exits the opposite edge, and removes the upper portion of the stone. This flake probably qualifies as overshot, at least to most people. I happen to think of it as a really low coast to coast flake, that looks like an overshot.
On the other hand, there is another kind of overshot flake that involves a ninety degree turn in the break, prior to reaching the opposite edge. This type of break lops off the far edge.
In my case, in January of 2015, I had an epiphany as to what caused the break to turn ninety degrees, prior to reaching the opposite edge. In my opinion, this is what a true overshot is.
I asked one of the posters why he thought that some breaks run flat, while others curve over the face of the stone. I am not sure that he noticed my question. But, I could take it one step farther. Why would a break run straight, but then curve at the last minute, while creating an overshot with a right angle turn? The second question is harder to answer than the first. Sometime, when my work is unbanned, and other people are allowed to see it, and discuss it, I might share more.
Anyway, here is an example of a straight run, followed by a hard right turn, prior to reaching the other side:
Here is the entire flake, by itself:
Now, if a person follows a really old description of the effects of pressure, and the pressure flaking process - in terms of force - what can be seen is that my work does not actually conform to the description, though my work is not actually entirely the result of pressure. So, why did the break turn at the end of its trajectory? Why did it turn, and cut off the opposite edge? Why didn't it run straight like a coast to coast flake? Does my deer tine contain some special magic? No. So, what is the answer?
By the way, I believe that Marty mentioned years ago that the initiations from his notched punch flakers are not quite like the initiations seen on ancient material. I believe he saw some difference. Well, my tine punch initiations probably do not look quite like his notched basal punch initiations. There are really two different types of flakers. And, that just leaves one question...
