Tech disc test driven development

[disc-golf-neil]

Started a playlist on YouTube for tech disc tests, the first one is comparing nose angle techniques. Turn the key, vs pour the tea, vs inverted swoop:

 

[disc-golf-neil]

Perhaps if I tried to dynamically pour the tea at the last moment instead of maintaining the wrist position, it would work better. However, if that worked better, I think it would be less because of the wrist movement and more because trying to do it dynamically and aggressively would increase the chance that you do something extra with the arm that helps bring the nose down

 

[Nick Carroll]

Perhaps if I tried to dynamically pour the tea at the last moment instead of maintaining the wrist position, it would work better. However, if that worked better, I think it would be less because of the wrist movement and more because trying to do it dynamically and aggressively would increase the chance that you do something extra with the arm that helps bring the nose down

I'm skeptical that last-moment usage of that cue could be consistent, or help overall, when it comes to drives. I spent an hour doing dedicated testing and at least for me trying to institute that cue at the tail end of my swing ended up in out-of-control releases of the disc, and the flights were embarrassing. That said, you might have better success than I with experimentation. After watching Sheep's video I'm more convinced than effort other form elements have to be in place for nose angle cues to work. (the grip is good, the swing is on-plane, and the follow-through is consistent with the swing (especially wrist angle)

 

[disc-golf-neil]

I'm skeptical that last-moment usage of that cue could be consistent, or help overall, when it comes to drives. I spent an hour doing dedicated testing and at least for me trying to institute that cue at the tail end of my swing ended up in out-of-control releases of the disc, and the flights were embarrassing. That said, you might have better success than I with experimentation. After watching Sheep's video I'm more convinced than effort other form elements have to be in place for nose angle cues to work. (the grip is good, the swing is on-plane, and the follow-through is consistent with the swing (especially wrist angle)

I agree about needing a good fundamental base first, but turn the key is timed in the same way I was describing testing out a timed pour the tea and without a lot of time using the turn the key cue I was able to get those nose angles on command with decent consistency, some here and there that are off, but that's true of other things too like hyzer control, spin, etc. You mind as well doubt all of high level sports if you're going to doubt that timing is possible to get consistent at.

 

[Nick Carroll]

The good news for you is that you're younger and have better form than I, and have less to "rewrite" for lack of a better term. You may be a lot more successful than me at dynamically making any adjustments or corrections in the swing. I still believe (maybe incorrectly, dunno) that minimizing actions during the swing, and setting things up properly before you even attempt to throw, may be the better course of action. But I think that's where experimentation comes in, and the results will speak for themselves over time.

 

[disc-golf-neil]

I tested 'no pour the tea' and 'unpour the tea' (opposite wrist movement) and they were both more nose up than my pour the tea. Will release a vid tomorrow. So it seems it works but for me only to get to nose neutral and not consistently nose down unless I use a more advanced dynamic technique.

 

[disc-golf-neil]

The good news for you is that you're younger and have better form than I, and have less to "rewrite" for lack of a better term. You may be a lot more successful than me at dynamically making any adjustments or corrections in the swing. I still believe (maybe incorrectly, dunno) that minimizing actions during the swing, and setting things up properly before you even attempt to throw, may be the better course of action. But I think that's where experimentation comes in, and the results will speak for themselves over time.

I did start out with 'set and forget' as my main strategy to offload as much cognitive overhead as possible to work on the other many form elements.

E.g., for 5 months:
1. set hyzer lean amount
2. set pour tea
4. set grip pressure
5. pick brace spot and runup line
6. set aim point and stare at it
7. set arm height for reachback height based on desired launch angle (aligned with Y axis of aim point)
8. runup on line to brace spot and just try to pull through on plane while everything else is set and maintained

I'm only now trying these dynamic things b/c I'm used to a lot of the other stuff and can actually quickly verify the results now with tech disc and because if I want to keep pushing my distance I need more nose down and set and forget pour tea wasn't cutting it. More speed will also help distance but lately that's been much harder to get than more nose down--low hanging fruit.

 

[koiyote]

It's definitely a workable cue. I think about golfers hitting that tiny ball with a tiny club head and pronating their hands or tennis players on a serve pronating and being able to hit a line on demand at 130mph. The human body is capable of learning how to time movements like this in other sports, so why not in disc golf?

 

[RowingBoats]

because if I want to keep pushing my distance I need more nose down

I tried to bring this topic up yesterday too because it does seem like 'more nose down' is becoming a goal.

I just don't think there is evidence for this, and anecdotally, I would say that simply getting a lower negative angle is not going to have much effect at all if you are throwing at least neutral or negative to begin with.

What is the reasoning to think you should pursue lower angles for more distance?

And what lines are we talking about. Maybe if you are talking about those kinda silly 'distance lines' then nose angle gets weird. I really only care about actual golf shots. I will practically never be throwing a flippy boy with 150' of right/left movement 50' in the air lol.

 

[disc-golf-neil]

I tried to bring this topic up yesterday too because it does seem like 'more nose down' is becoming a goal.

I just don't think there is evidence for this, and anecdotally, I would say that simply getting a lower negative angle is not going to have much effect at all if you are throwing at least neutral or negative to begin with.

What is the reasoning to think you should pursue lower angles for more distance?

And what lines are we talking about. Maybe if you are talking about those kinda silly 'distance lines' then nose angle gets weird. I really only care about actual golf shots. I will practically never be throwing a flippy boy with 150' of right/left movement 50' in the air lol.

Yeah it's mostly for when I have a big open fairway and want to bomb. Even tho it doesn't happen that often, some courses have more of them and I want to be able to go for it.

Part of the idea is, if -4 is truly good, but -4 only happens when the stars align for you, then you will rarely be able to pull it off. However, if I can fairly consistently get beyond -4 then it makes -4 much easier to achieve and I can shoot for -6 and miss and still be -2 to -4.

If what people say about nose angle is true, you can use less effort (less speed) with more launch angle and lower nose angle to get distance by taking more advantage of the pushing glide phase at the apex.

Just need to confirm that negative is actually useful. I asked @Nick481 in his thread since he has aerospace background, maybe he knows about academic flight papers that can back it up.

 

[RowingBoats]

Yeah it's mostly for when I have a big open fairway and want to bomb. Even tho it doesn't happen that often, some courses have more of them and I want to be able to go for it.

Part of the idea is, if -4 is truly good, but -4 only happens when the stars align for you, then you will rarely be able to pull it off. However, if I can fairly consistently get beyond -4 then it makes -4 much easier to achieve and I can shoot for -6 and miss and still be -2 to -4.

Just need to confirm that negative is actually useful. I asked @Nick481 in his thread since he has aerospace background, maybe he knows about academic flight papers that can back it up.

I don't really doubt the value of a negative angle itself. Pros seems to consistently be tossing with a slightly negative angle naturally when they throw a techdisc. I do have my doubts that going more negative has any actual benefit though.

My hunch is that discs anywhere from 0 to -5 degrees or something all just end up flying neutral. With nose up, there is a rim for air to perpetually be pressing against, not letting the disc have any chance to ever flatten out. With nose down, I can imagine the air just kind of presses the disc's tail into a neutral flight. This is an intensely unscientific theory lol, but it would make sense if that is what ends up being the case.

 

[disc-golf-neil]

I don't really doubt the value of a negative angle itself. Pros seems to consistently be tossing with a slightly negative angle naturally when they throw a techdisc. I do have my doubts that going more negative has any actual benefit though.

My hunch is that discs anywhere from 0 to -5 degrees or something all just end up flying neutral. With nose up, there is a rim for air to perpetually be pressing against, not letting the disc have any chance to ever flatten out. With nose down, I can imagine the air just kind of presses the disc's tail into a neutral flight. This is an intensely unscientific theory lol, but it would make sense if that is what ends up being the case.

That's my instinct too and why it tracks when I heard someone talk about some aerodynamics of disc flight academic paper (can't remember where or who) and they mentioned the "disc doesn't fly with the nose down" it levels out. I'm assuming that extra nose down just reduces the risk that say a gust of wind comes at an undesirable angle and pushes it from nose neutral to more nose up early on in the flight so extra nose down maximizes the chance that you get to the apex with a neutral enough nose to get long glide. Also extra nose down lets you use extra launch angle without it stalling which I can imagine can be helpful sometimes. Often you see in distance competitions people not give it enough height because the margin of error of going too high is so small for them. But if you have the ability to get extra nose down you have less margin of error for too positive of a launch angle, but you have more margin of error for too low.

 

[RowingBoats]

That's my instinct too and why it tracks when I heard someone talk about some aerodynamics of disc flight academic paper (can't remember where or who) and they mentioned the "disc doesn't fly with the nose down" it levels out. I'm assuming that extra nose down just reduces the risk that say a gust of wind comes at an undesirable angle and pushes it from nose neutral to more nose up early on in the flight so it maximizes the chance that you get to the apex with a neutral enough nose to get long glide.

I can see that, and I can also see value in making extra sure you don't throw nose up. Very curious what my nose angle numbers end up being. I could be totally wrong about the feeling that I mostly throw neutral. All I really know is that I have never tried to change much once I started to see the disc with the lowest profile possible in the air.

 

[Nick Carroll]

One thing to keep in mind: that initial nose angle (relative to launch angle) is temporary. As the disc spins and moves, I am pretty sure the nose angle of the disc quickly assumes the trajectory of the disc, due to the gyroscopic effect. I know it's a bit more complicated than that, but I think it's the same as how wobble diminishes over time.

 

[RowingBoats]

One thing to keep in mind: that initial nose angle (relative to launch angle) is temporary. As the disc spins and moves, I am pretty sure the nose angle of the disc quickly assumes the trajectory of the disc, due to the gyroscopic effect. I know it's a bit more complicated than that, but I think it's the same as how wobble diminishes over time.

I think this is likely true for nose down throws but the disc definitely doesn't re-align to neutral if it is nose-up.

I imagine that is what you are saying though

 

[Nick Carroll]

I think this is likely true for nose down throws but the disc definitely doesn't re-align to neutral if it is nose-up.

I imagine that is what you are saying though

Maybe I'm wrong but I think it does that on nose up throws, too. The trajectory of the disc gets affected by it either way. That said, this is way outside of my area of expertise. I guess it's fair to say it's just an area of interest!

 

[Brychanus]

That's my instinct too and why it tracks when I heard someone talk about some aerodynamics of disc flight academic paper (can't remember where or who) and they mentioned the "disc doesn't fly with the nose down" it levels out. I'm assuming that extra nose down just reduces the risk that say a gust of wind comes at an undesirable angle and pushes it from nose neutral to more nose up early on in the flight so extra nose down maximizes the chance that you get to the apex with a neutral enough nose to get long glide. Also extra nose down lets you use extra launch angle without it stalling which I can imagine can be helpful sometimes. Often you see in distance competitions people not give it enough height because the margin of error of going too high is so small for them. But if you have the ability to get extra nose down you have less margin of error for too positive of a launch angle, but you have more margin of error for too low.

Also wanted to say and maybe Nick K can weigh in:

GG's lines of attack are also a little atypical because it's not only more drastically nose down, on hyzer, and higher spin rate (I'm curious what Nick would say about gyroscopic stability ideas there), but he's often lobbing them very "upward nose down" on one of the most aggressive high lines of attack out there.

I kind of think of it like lobbing a bird up in the air nose down with its wings initially tied, and then the string breaks and it's free to glide/fly somewhere on the parabola, the nose is leveling out as you describe etc. That's a crude metaphor and obviously a disc always has its wing deployed, but just trying to point out an opportunity to discuss the parabolic arc of the thrown object interacting with the rest of the good stuff. GG is lobbing that birdie 74 mph on a high arc in the context of the rest.

 

[Brychanus]

Oh not really a coaching point but one last little systems theory tidbit for the people who are interested in form "forward and reverse engineering":

At some point in their journey, engineers, economists, dynamics systems scientists, and really anyone interested in mechanical systems learns about Goodhart's Law. All the links under "See also" will quickly take you on paths to some of the dangers of just training to the data. These are not just details from academia, but fundamental systems concepts that do things like keep airplane control systems working.

You'd be reading my intent wrong as a criticism of TechDisc specifically (I've said I've used it too). One incorrect interpretation of Goodhart's law would be to become aware of it, then suddenly stop believing a new technology is valuable with no further criticism. That is almost one exactly wrong interpretation.

More generally, there is a reason that systems engineers are trained to be thoughtful about what we know about the systems that mediate outcomes and be aware that often hard to predict and unwanted consequences can emerge just by trying to "overtrain" to the outcome measure.

What do you do about it? Well, ten engineers give you ten slightly different answers, but multiple methods of observation, knowledge and measures of mediating mechanics or "latent" states in the system, and interplay between theory and data is often the long run elixir. I.e., an exchange between forward and reverse engineering.

I'm optimistic that in the long run that there's consensus here on much of what neil and others are doing vs. other "forward engineering" concepts. I think a lot of it is already out there, but people are just using different words and emphasizing different things about the same or different things at the same or different times.

 

[Nick481]

I had responded to @disc-golf-neil in my warmup thread, I'll paste it here really quickly:

Regarding my mention of -4 degrees being a good general nose angle:

"It's more of empirical evidence driven by tech disc data and field results that led me to that, and I need to be careful with how dogmatically I state an ideal angle number because I'm also suspicious that more negative nose angles (like GG) may produce better results in certain situations.

From what I understand, tech disc is using some kind of distance calculation using either data-fitting regression equations or a numerical, iterative flight simulator that is physics-based. They did an incredible job with it and I've been so impressed by their execution, but it's still a bit of a chicken before the egg issue, and is hard to measure real flights and all of the associated data (spin, nose, etc) if throwing a non-tech disc to compare it against.

For example, I think on high, flip-up hyzer bombs, super negative nose angles greatly enhance distance. I threw -7 deg (measured with photogrammetry) last week on one, and got it out to 510ft which was further than my usual. I think the low nose helped stave off the stalling, high AoA phase that happens as the disc falls back into fade (descent rate increases).

For distance lines, I've noticed that anything below 0 degrees doesn't help as much, because as the disc goes into its extreme turn and anhyzer tilt, the velocity vector shifts to the right and then the angle of attack greatly decreases (effective nose angle becomes negative). Still playing around with that though! I think it comes down to a million factors and people like GG naturally figured out what's optimal for their individual throwing style."

 

[Nick481]

Another thing I forgot to mention about GG is how his high spin rate provides more gyroscopic stability, which fights the precession that occurs as a result of the negative pitching moment (when AoA is negative) and positive pitching moment (when AoA is positive). I'm suspicious this allows him to throw his lines of choice with less variance in AoA from release to landing, which can help a lot with minimizing the drag that comes with generating lift from positive AoA's at the end of the disc's flight (when descent rate is high).

I really need to do a deep dive into researching it more and then make a video because it would be a fun conversation.