Walter...
I really don't know when the SLP was "first" discussed as such. I was keenly aware of it as far back as 5 years ago, but most of us used the concept of good tracking and a straight path of the rod tip to avoid either, "doming", the formation of a big inefficient loop, or the concave rod tip path yielding a tail many years before that.
Your are right.....that English 5 L note would have fallen into the water as the caster mobilized the elbow.
Freeing up the elbow was mentioned as the prime way for Paul to become an uncommonly good caster in, A RIVER RUNS THROUGH IT.
Lefty taught this as well as the elimination of the use of the clock face over 30 years ago.......and he doubtless wasn't the first. ["Clocks are for telling time, not for casting."....Lefty]
My own grandfather "opened up" his elbow over 60 years ago.....I remember that well.
As you look at the photos of John Tarantino and other great tournament casters of yore, you see them derive distance from a the use of a long stroke which would have been impossible with the elbow "nailed" to the ribs.
Check out some of the pictures taken in the 1800's in Cliff Netherton's, HISTORY OF THE SPORT OF FLY CASTING, EARLY TIMES. (PP 369 AND 370) Also the picture of Call J. McCarthey, (All-around National Champion, 1914, 1916 and 1920) on p. 222 of Cliff Netherton's, HISTORY OF THE SPORT OF CASTING GOLDEN YEARS.
Your comment about the line's momentum helping to maintain a straight path, is only true if the rod tip assumed that path. That very momentum will drive that line around in a vertical curve path , for example, if that's what the rod tip did during the stroke.
Then, too, these stream casters on small English chalk streams usually were not trying for much distance. That made their very limited techniques sufficient for that kind of fishing. A very different situation for the distance tournament casters.
Lastly, you are correct that the casting hand can move in an elliptical path as the rod flexes so that the rod tip moves in a more or less straight path.
Gordy
From: Walter Simbirski <simbirsw@xxxxxxx>
To: Gordon Hill <hillshead@xxxxxxx>
Subject: Another question about casting history
Date: Tue, 20 Dec 2005 23:29:04 -0700
Gordy - At what point did the concept of the SLP of the rod tip become widely understood?When we look at old casting instruction material the basic stroke talks about 10 o'clock and2 o'clock ( or some variant) being the ideal stopping positions for false casting. No real mentionof the slp of the rod tip that I know of. At the time the casting stroke was also more restrictivethan it is today - for example Mel Krieger talks about being taught to cast English style with a5 pound note held between the elbow and body. If the caster moved his upper arm the 5 poundnote would fall into the water and be lost.Based on this the basic casting stroke at the time consisted of moving the lower arm in roughly30 degree arc and using a bit of wrist flip at the end to accelerate to the stops at 10 and 2. Atthe start of the forward cast the lower arm would be nearly vertical with the wrist cocked so thatthe rod was at 2 o'clock. Now if we swing the lower arm forward and the rod was too stiff tobend the rod tip would follow a convex path to the top of its arc and then begin to drop quicklyas the direction of the rod hand moves farther into its circular motion, i.e the rod tip would movein a doming motion. But since the rod flexes very easily at the start of its forward motion the tipwould naturally follow a slp if the "proper amount of power" is applied. Since the line's momentumgives it a tendency to follow a straight line there is a certain amount of forgiveness in the"proper amount of power". Follow up with a bit of wrist motion and the completion of the hand'smovement along its natural arc and you get energy transfer and loop formation happening naturally.Sort of a "natural casting stroke" if you like. Nowadays we abandon the idea of the clock faceand concentrate on the idea of slp of the rod tip providing for a lot of variation in the basic castingstroke.Walter