in search of a perfect loop


Tropical member

I am begging you... could you just leave us alone?! I promise I will get back to you when we finish those fundamental issues in the original post.
Just leave us alone for few more days....much appreciated!! sincerely, Mark


still an authority on nothing
Sorry bro, but I'm wondering when you're going to leave US alone.
The fundamental issue is the question I just asked you, the question you opened the thread with, the question you keep dodging.
Reference post # 64 and post #164.
I have all confidence you'll get to the point eventually.
A casting theory that states dissipation of energy away from the line of travel helps is pure crap, and I'm not waiting a few more days for you to work it out.
Dude! read the responses! starting with post #2!

BTW, early release on an overhung head doesn't count as direction change. Let's see some meat.
Hi Bruce,

I agree! even the rod tip dipped into the water, the stop should happen early on, thus caused the rod bend into the other direction. I wonder if you can point out where he stop the rod? maybe it is hard to depict, but I will love to know where is your estimation. Thanks! Mark
Mark, I'd say the stop occured some where between clip 3 and 4. If there was two additional clips equal spaced between three and four, I'd think we would see the stop at 3.33 and the release at 3.66...if that makes any sense. I do appreciate the time lapse "like" clips, they really demonstrate the effects of overhang.

By the way are you trying to skew the data? Clips 2 and 3 are so close together then hello where's 4? Oh here it is...demonstrating downward pressure! Just kidding Mark, it's gotta be hard to stop those clips just right.

After a closer look, I'll say more like 3.20 stop and 3.40 release...Bottom hand postion in clip three leads me to believe stop is!James.


Tropical member
Hi friends, here is the superimposed diagram of release / stop points in two power applications (hammer throw and skagit cast)

V1: the speed of hammer being released
V2: the speed of skagit line system being released

VR: Rod tip downward speed

Dash line: projected horizontal line (projected loop/hammer direction)

CM: center of mass (hammer) (Noted: the center of mass of the skagit line system should be a bit toward back... this point is a simplified version for demonstration purpose.)

ICR: instant center of rotation.
this is our pivot point during the forward stoke, accounting the rod bend into the equation. this is the rotation forces calculation should be based upon.

Overall, you can see this superimposed diagram as my "final answer". the overhang and skagit line system play a very important roles in this concept. the instant center of rotation (ICR) is also another very important concept to dissect the dynamic rotation action during the forward stroke. Because this is the calculation of rotational forces based on. If you understand this diagram, extend different overhang lengths will have different results... you might want to test this idea in the field, vary overhang length, and vary different skagit head + sinktip+ fly combinations. See how different component play roles in this rotation motion. Time of releasing is also important, it will determine the angle of projected loop direction. see Trebuchet video explanation. Mark
In reference to post #169:

"Final answer?" Somehow I don't think so, but to conitnue on in the game show metaphor: "V1 V2 VR CM ICR"

Pat, I think I'd like to buy a vowel.

Spazz, I believe it's your spin...

At this point, I'd like you to take a moment and tell me (us) what statements about casting you believe this thread supports. I'll ask you to step out of the analogies and speak only in terms of water, line, rod and casting stroke.

I'll suggest that you have a case here for claiming that:

A high, hard stop is not absolutely necessary for a tight loop

Overhang facilitates the elimination of a high, hard stop

Beyond that, I'll suggest that you may want to be careful that you aren't letting the analogy lead your thinking. I think it is also worth pointing out that this isn't new news. People have been "slinging" line, especially in my little corner of the world, for some time now.


Tropical member

At this point, I'd like you to take a moment and tell me (us) what statements about casting you believe this thread supports. I'll ask you to step out of the analogies and speak only in terms of water, line, rod and casting stroke.

I'll suggest that you have a case here for claiming that:

A high, hard stop is not absolutely necessary for a tight loop

Overhang facilitates the elimination of a high, hard stop

Beyond that, I'll suggest that you may want to be careful that you aren't letting the analogy lead your thinking. I think it is also worth pointing out that this isn't new news. People have been "slinging" line, especially in my little corner of the world, for some time now.

Dear Trevor,

You are absolutely right! I frequently remind myself what is the thing I did not see? Are there other possibility? What other not considered factors? Is this useful for real fishing? I am serious and sincerely say so … those elements are part of my thinking. In reality, I am eager to learn something new from others…I don’t want to waste my time just be offering or stirring … there is less benefits for myself for doing so… the reason I enjoy sharing ideas are two folds. First: I enjoy share information in the place I love and search for same minded people. Second, get schooled and learn something news and move on… I am not a big fan of a mud fight, because I don’t even cuss… what is the point to stir the mud fight?!

Over years, I have meet some of really good friends from this website, being original from Washington, I can tell you this website is my home, and I treasure those friendships as heartily as my true brothers in town. Thus, I post those ideas here to share and hope others will enjoy. My ideas might be wrong like other scientific hypothesis that failed to fulfill all conditions. Thus all the positive, constructive opinions are all welcome! ! IF someone can find a way to convince me the earth is flat, I will more than happy to learn!! But it has to be using valid scientific principle to demonstrate it though. We, as reasonable adults, don’t fooling around with bogus, it’s just a waste of life.

In addition, I agree there is nothing new in slinging overhang, I absolutely agree. If you read my first post, it states clearly that straight rod tip path is not a required element in creating a tight loop. Then I state the new concept of power application which I also working out the mechanics of rotation into this complex motion. Casting a fly rod with overhang is nothing new, but using distinctive physics principles (CM, ICR, Angular acceleration) to explain it is a NEW concept. One of my good friends’ whole PhD dissertation is just to describe how tidal force shaping the river mouth. Is this something new to you?! The NEW thing is the idea and concept that he integrated, articulated those simple physics principles to explain the complex river behavior.

What is the implication of all those discussions? To me, it all tie back to the real fishing situation. If you are using overhang and SHORT shooting head system, don't be afraid to use sling shot and rotation motion to shoot the loop. The loop will not give you a hard time as the straight rod tip path concept suggested. Instead, there are about 30% power will be generated by the downward stroke as I suggested in the earlier post. Good discussion and good fishing!

Sincerely, Mark

(BTW, just let you know, Tellis' shrinking loop after line releasing will need more explanations... but I have no interest in posting them here...cheers)

I've always enjoyed your posts, and appreciate your willingness to take a risk and challenge conventional thinking.

I am having some trouble on this thread, though. Regarding the question of a straight line path, I'll certainly agree that as the rod continues to unload it becomes increasingly unimportant to maintain a straight line path, but as the rod is imparting it's maximum input to the line, it needs to travel in a straight line, if only briefly. By design, a rod more or less handles this for us, by flexing more deeply as it loads and straightening as it unloads, tracing an essentially straight line where a broomstick would make an arc. It needn't be strictly straight through the entire process, but just as a hammer face should be flat as it strikes the head of a nail, the fly line should at minimum follow the the rod tip in a straight line as the rod is imparting it's maximum input.

If you go back and look at your video stills, the line is following the tip in the 2nd & 3rd frame, and those are the moments where this cast is being made. What he does after the 3rd frame really isn't that important, as the rod is already unloading. When I watch that video, I see a flat anchor set with too much stick that necessitated a hard forward stroke with follow through. The dip you see in the top leg of his loop in frames 4,5 & 6 is evidence of the fact that he hammered the rod because he knew he had a bit too much line on the water. He failed to move the tip in a truly straight line when it mattered. The cast immediately before :)43), viewed from the back, exhibited better timing and less effort on his part. The top leg of the loop was flat for the entirety of the cast, whereas the still frame loop only tightened nicely at the end, as a result of drag on the line.

Regarding your hammer throw analogy, I actually think it is more useful in describing poke wraps and skagit double sweeps in the horizontal plane as you very obviously pull towards the center against the apex of the d-loop as the line sweeps around you. The problem with using it to describe the forward stroke, is that the ball is a concentrated mass and a fly line has it's mass distributed over quite a length. The only way to pull against the entirety of a fly line is to straighten the line out and pull against it in that straight line. You cannot pull perpendicularly against one end of the line and be pulling against it's mass, so as you depart from the straight line by following through on the forward stroke, you cease to impart additional speed to the line, and only provide pulling tension through the line as necessary to help the outbound energy free the line from the water.

I'm not trying to be contrary, and I don't want to discourage or dissuade you from describing the physics involved in casting, but I think you might be stretching the usefulness of the hammer throw analogy. If they were truly analogous, I would expect to feel lift or a need to pull down towards the center on the forward stroke, and I don't, at least not nearly to the degree that I feel I am making an effort to unload into a straight line. Needless to say, there is a rotational aspect to the forward stroke, but I believe fly rods are at least in part designed to translate rotational input into a straight line, as that is what the line wants.


Tropical member
Dear Trevor, my friend.

I reread my post, it sounds a little bit harsh to you... sorry, not a little bit to that regards...
Thanks for brought up good points as always! You are one of the few people I mentioned earlier (the same minded people) that I enjoy to interact with..

well... briefly to give a quick response here (more detail will sent you through PM).
As you can see the diagram is a little bit busy... sorry, but this is the most simplified as I can do.

First. I agree, the line is not a single rigid object like hammer. Line is a system. Including head, tip and fly + sticking on the water. The last part is important, system is buried in the water when we doing skagit cast. so the system need to considered as a WHOLE and imagine it's center of mass. Easy analogy would be trying to do the same cast on a grass lawn, you will lost water grip, you will also shifting the CM. As I mention earlier, and per Greg's good experiment, the water grip is open up the possibility for us to do some crazy upward circular motion. the entire system provide some "acting and reacting" effect. This is a very complicated concept because the CM is hard to picture in this line configuration. But you can tell the difference when you practice skagit cast on the lawn (less upward rotation), on water (more upward rotation allowed). look at the Josh Linn's video more closely, he set the poke GENTLELY. But as soon as the line set in, he RIP it hard in a small circle to produce this sticky "acting and reacting" force to propel the line in front of him. You can try to test this on a grass lawn. I bet you will see the line fly in the air and land as a pile...

Second, (the forward stroke after the point A)
If you look at my diagram again, you will see the overhang is rotating after the point A (old diagram). This is NOT the traditional straight rod tip path (Chris video) suggested. It will suggest you stop on the same line path and let the overhang to run over it. But instead of doing so, I suggest you to pull the line DOWN. to ROTATE the overhang. It seems this is unnecessary work, because line is already know where it should go (straight path - the dash line).

However, I argue this is necessary downward stroke, and will give you 30% more power. (please test this and I eager to read the reports). The reason being, the Center of the Mass of line system are still lagging behind the optimum leasing point (not on the hammer's point YET) when your rod tip reach the point A. They (CM) are way behind, so in order to extract the maximum power we need to KEEP drag the CM forward by using the rotating overhang. (very important). This motion is STILL adding forces to the line system (to the CM of the line). Until the real CM of the line system reach the hammer's position, then we will let the system go. At this point, you can picture the overhang almost reach the 90 degree angle to the horizontal path. This can be seen in Tellis frame by frame analysis (although I did not capture the real moment). I agree this is very hard to picture, but luckily this is not very hard to exercise in the field. I suggest you can do a longer overhang than usual, then put a MASSIVE downward force to see if you can OPEN up the loop. most of the time I am amazed by my own experiment... the loop just shoot right out in a tangent horizontal direction.
The logic also lie on the new diagram I just draw this morning. see the VR: speed of rod tip (it can be dissect to two separate forces V2 and V down). As soon as your rod tip still on a angle, you always has a partial V2 to the front, this is the "useful" forces you can use during the downward stroke. (although I agree this depends on how long is in your overhang---see my ICR explanation) the longer the overhang, the longer and more acceleration you can adding into it. BUT you also will running into a danger of loop collapsing.

Hope this help... good discussion! Mark


still an authority on nothing
I think the real answer to Yuhina's original premise lies in post#176, just don't watch it twice.
But it's the best display of the rational use of angular momentum in this whole thread...answers the question of where that extra 30% really comes from. Good god, look at that downforce.:clown:

Mark, your diagram in #169 does not look like any cast I've ever done, or ever seen. It does however, look like a guy setting up to dump a poke. From the bend of the rod it seems the caster is barely in touch with the line, and no significant power transfer is taking place.
I don't fault that, I'm no artist either. Guess we're soul brothers that way.:thumb:

I don't believe that this concept holds water, that its a concept which deviates from solid casting mechanics, and that, rather than being the topic of your doctoral dissertation (which will change the casting world), it will quietly gasp, like a sucker tossed on the bank, till it dies and is forgotten.

However, we have almost established tradition here, so we won't drive the stake into it's heart till we reach thirteen pages...after all, etiquette is almost as important as good casting mechanics in our world. I admire your intelligence, your persistence, your tact in the presence of some consciously over-the-top provocation on my part, your drive to understand the many things I admire about you. Unfortunately, this theory is a steamer. So get into damage control mode, the train's a comin'. Or maybe not. You come up with some even more batshit crazy claims than this, you may hit the magic 20...rare for December.

Happy Solstice buddy, the days are getting longer from here on out.:thumb:

disclaimer: no suckers were harmed in the making of this post. I let them go live.

Your notion that a live line has a 'center of mass' is where I think you are letting your hammer throw analogy lead your perception a bit. The only situation I would construe a fly rod to be addressing a line's CM is when the line is straight and the direction of pull is along the length of the line. When you pull against a d-loop, you are pulling against kinetic energy as expressed by the line. When the line passes over your head, there is no upward oppositional vector to pull downward against. There is kinetic energy in the form of an outbound line passing over your head, and you are tasked with shaping it into a loop. The opportunity to add energy to it has for the most part past. By following through and pulling downward, you are pulling line through a system shaped by kinetic energy. The follow through is akin to a haul that you might use to assist a fly in turning over at the end of the cast. When you give the fly line a little yank to turnover a fly, it turns over, but always lands shorter than where it wanted to, but wasn't able to go. You are pulling line through the system, but you aren't actually adding much energy to it. The follow through will contribute to pulling a fly free from the water, though, and that has implications for an outbound line that would have struggled to free the fly otherwise. The additional power you are sensing is coming from the straight line path of your forward stroke where you are bending that rod with no intention of stopping it. You simply can put more force on it over a longer distance when you don't have to plan for a stop, and the overhang lets you get away with it. What you are forgetting with your vector drawings of the rod in a downward position is that the rod tip is slowing as it has largely unloaded at that point, while the fly line is traveling at a higher speed. The tip is beyond being able to contribute speed at that point, it can only pull line through the system and increase tension to the fly.

I have played extensively with overhang and never really used a high stop when slinging line for distance. I have done the experiments you suggest.

Best Regards,


Latest posts