Top Junior Ladies jumps traits (Height, Speed, Prer, Delay)

https://www.sports.ru/tribuna/blogs/ternovblogfk/2237837.html

IMO it is extremely interesting statistics - albeit in Russian (you still can use google translate) but with clear enough graphics and tables. It covers so far juniors from this season (mostly russian and japanese) and author promises to make article about seniors later. Measurement methodology is explained in detail in his earlier articles from last season about the same jumps traits (however there were only height and rotation speed then) of juniors and seniors (you can found them if you click on author name there and scroll down the list). In short - mostly it was done with large amount of video frames measurements and some formulas from geometry and physics applied.
Enjoy! :agree:

P.S.: it will be amusing to see how many myths of "true jump technique" skaters admirers would be destroyed - since almost all ladies skaters on almost all jumps ALWAYS PREROTATES to at least 100-150 degree on average In other words if one would want to downgrade jumps due to prerotation - ladies even now would be limited to double jumps only except couple of lutzes/flips from couple of jumpers.

P.P.S.: I am not agree with author's final conclusions since he clearly is not willing to include ladies quads jumps height to affect the standings (probably he thinks it's too unfair or something) - but oh, well :sarcasm:

P.P.P.S: I like his reasoning about jump traits meaning - in relation to UR and GOE. Height affects GOE positively and lessens UR probability, rotation speed just lessens UR probability, prerotation affecting GOE negatively (only in theory though, in practice - almost never) and lessens falls and UR probability, delayed rotation affects GOE positively and increase UR and falls probability. So in the end all the most "correct and beautiful" jumpers jumps with the most inefficient and nonoptimal technique - resulting in frequent UR and falls, and very hard to rotate cleanly 3-3 combinations. And even they can't jump this way Toeloop, Loop and Salchow.

I generally like these kinds of analyses even though I think they have the potential to be taken more seriously than they should be. There's an attempt at objectivity that's sorely lacking in skating and it doesn't resolve around some completely nebulous, made-up fan standard for greatness. Plus, it's the sort of thing that can give useful information: there should really be a basis for determining what counts as "very good" height or "average" or "poor" which is lacking at the moment, and studying who consistently jumps the highest and how those jumps tend to look in the moment would be a better standard than "judges eyeballing it completely against individual benchmarks that they also eyeballed completely the first time." And also for things like determining the minimum airtime for jumps, given a skater's rotation speed and technique, and how much more height they need to achieve, or how much more quickly they need to snap into rotation instead, etc.

There's still an issue of subjectivity even with something like this, though. Mishin or Krall doing these estimates with 100+ fps cameras and nice angles is different from doing them with 24/30/48/60 fps YouTube videos, which the author acknowledges. But even using what are presumably similar framerates, two people looking can come up with totally different estimates. Last time I saw these tables I consistently came up with higher numbers and this time, I consistently came up with lower numbers.

(It's also different from, say, Dartfish. And these max rotational velocity estimates I consider unacceptably handwavey, so I ignore them.)

Since I'm side-eyeing quite a few of those numbers, I guess I'd add my own estimates for the few that I checked (JGP only), since I would trust both of our estimates together more than either on their own.

Here are all Yelim's heights per me, since she was at the top of the first table:

And here is whoever topped the list for each individual triple:

Some random observations: Yelim can do a fantastic 2A (my very highest estimate, which got averaged down, matched the 44 cm from the source) but she also does it as the very last jump in the FS, and so unsurprisingly those attempts are way lower. Trusova has very consistent heights on her triples in combination whereas someone like Kostornaia varies significantly in height on the +3T, and not necessarily depending on the jump before it (but all of them are huge).

As for the "efficient and optimal" debate, well, failure vs. success matters. But I think that skaters who can successfully pull of jumps using "correct and beautiful" and more difficult technique should be additionally rewarded over those who can not. For those that can't pull it off, then, oh well: there is such a thing as "average."

Interesting to see that Japaneses' jumps depends more on height while Russians' more on rotation speed.

Interesting. Referencing their data from last year, Trusova's 4T height is greater than Yuzuru Hanyu's, Nathan Chen's, Shoma Uno's and Javier Fernandez's to name a few male skaters.

yume said:

Interesting to see that Japaneses' jumps depends more on height while Russians' more on rotation speed.

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For triples, it's closer to that. But it's not so black and white because, for example, Alena Kostornaya has huge jumps too (like -3T). For quads, the Russians have huuuuge height - it's really impressive

Shayuki said:

Interesting. Referencing their data from last year, Trusova's 4T height is greater than Yuzuru Hanyu's, Nathan Chen's, Shoma Uno's and Javier Fernandez's to name a few male skaters.

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lol

Shayuki said:

Interesting. Referencing their data from last year, Trusova's 4T height is greater than Yuzuru Hanyu's, Nathan Chen's, Shoma Uno's and Javier Fernandez's to name a few male skaters.

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i think aside from height, it would be interesting to manage the distance covered.
There are skaters who jump kind of straight up, and skaters who jump "horizontally", covering great distance.Trusova's 4T goes pretty much straight up (you can see in the article gif).
Not sure about Fernandez and Nathan, but Hanyu, afaik, seems to cover more distance with his jumps, and Shoma's jumps are small, so its not surprising.

Interesting in the part about pre-rotation, the first skater definitely pre-rotates the most but lands the jump with the fullest rotation, whereas the other two pre-rotate less but squeak out the rotation on the landing a bit more. With some folks obsessed with pre-rotation, this is something worth noting.. if a skater pre-rotates, it's not ideal technique, but in some cases they could have equal or more rotation that other skaters who pre-rotate a bit less, depending on how around they are on the landing.

moriel said:

i think aside from height, it would be interesting to manage the distance covered.
There are skaters who jump kind of straight up, and skaters who jump "horizontally", covering great distance.Trusova's 4T goes pretty much straight up (you can see in the article gif).
Not sure about Fernandez and Nathan, but Hanyu, afaik, seems to cover more distance with his jumps, and Shoma's jumps are small, so its not surprising.

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Lol... riiiiight.
https://www.youtube.com/watch?v=AffXxve5juk

Why is rotating on the ice after landing mean less rotation than rotating on the ice before (pre-rotation)? Wouldn't they be doing the same amount of rotation overall? Surely the rotating on ice after landing could be classed just as not ideal technique as well but somehow pre-rotation gets a pass when that doesn't? Why aren't they punished the same way?

epicdreamer said:

Why is rotating on the ice after landing mean less rotation than rotating on the ice before (pre-rotation)? Wouldn't they be doing the same amount of rotation overall? Surely the rotating on ice after landing could be classed just as not ideal technique as well but somehow pre-rotation gets a pass when that doesn't? Why aren't they punished the same way?

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Because figure skating jumps have always been primarily about the quality of the landing.

Historically, and even currently, when we talk about a program where the skater "landed 7 clean triples", the clean is referring to the landing. It didn't matter if the skater pre-rotated, or flutzed, or had a mule kick, or had a leg wrap, or had poor height, or telegraphed the jump, or had a lean in the air. The landing is what (most) people care about first and foremost. Of course, these things are now covered in GOE, as they should be, but when it comes to the primary execution of the jump, the focus is on the landing (and that extends to rotation).

Is there any data on senior ladies? I’d be interested in ladies height and rotation velocity over time (from juniors to seniors). This info may be useful to predict who is more likely to have long term success with certain jumps as they transition to seniors. I have a feeling someone like Sherbakova might have more difficulty maintaining her quads as she seems to depend on very fast rotation speed. And I’d imagine rotation speed slows down as girls gain more physical maturity (wider hips) that will impact moment of inertia (decrease in the change of mass brought to axis of rotation due to shift in body composition e.g. mass around hips? I’m rusty in physics, so correct me if I’m wrong).

They changed it to include Trusova's 4Lz rather than 3Lz since they had picked 4T over 3T. With that, she is the new leader in height over Yokoi with 264.4 cm to Yokoi's 255.9 cm.

Sugar Coated said:

Is there any data on senior ladies? I’d be interested in ladies height and rotation velocity over time (from juniors to seniors). This info may be useful to predict who is more likely to have long term success with certain jumps as they transition to seniors. I have a feeling someone like Sherbakova might have more difficulty maintaining her quads as she seems to depend on very fast rotation speed. And I’d imagine rotation speed slows down as girls gain more physical maturity (wider hips) that will impact moment of inertia (decrease in the change of mass brought to axis of rotation due to shift in body composition e.g. mass around hips? I’m rusty in physics, so correct me if I’m wrong).

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Here is data for senior ladies from last year: https://www.sports.ru/tribuna/blogs/ternovblogfk/1400457.html

Tomoe has got some massive jumps, but that was pretty obvious. They're gorgeous. Her rotation speed is on the slower end. Anna has the opposite effect on her triples - fastest rotation but low. Sasha seems to hit the jackpot with having the combination of great height and rotation speed; I'm convinced that her jumps will be the most likely to survive puberty of the juniors.

What is more preferred, height or distance? Obviously both, but the force applied is the combination of both vectors, so maximizing one does minimize the other. Just by eyeballing it, Hanyu's jumps cover a lot of ice, where as Kolyada's jumps are enormous but go up and down.

And is it better to have the same height and rotation on triples and quads? For these ladies, their quads are much higher but the triples have just enough height for them to land the jump. Where as with Kolyada, he always goes for the huge jumps which is why his 3Lz always looks like a popped quad - which I personally find less aesthetically pleasing.

Shayuki said:

Interesting. Referencing their data from last year, Trusova's 4T height is greater than Yuzuru Hanyu's, Nathan Chen's, Shoma Uno's and Javier Fernandez's to name a few male skaters.

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Shoma I can understand but Yuzu and Nathan? I'm not sure about that.

:think: I find it interesting how Trusova has high jumps but they do not cover much ice.

leoleo said:

:think: I find it interesting how Trusova has high jumps but they do not cover much ice.

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Whatever she’s doing...she’s doing it right. Some of the best looking jumps I’ve seen :dance:

epicdreamer said:

Why is rotating on the ice after landing mean less rotation than rotating on the ice before (pre-rotation)? Wouldn't they be doing the same amount of rotation overall? Surely the rotating on ice after landing could be classed just as not ideal technique as well but somehow pre-rotation gets a pass when that doesn't? Why aren't they punished the same way?

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All jumps have a certain amount of inherent pre-rotation. (If you ever count how many revolutions a skater makes in air, you’ll notice right away that a quad does not involve four full revolutions in air, and for good reason.) Per ISU, if pre-rotation reaches 180 degrees — or a forward takeoff for any non-Axel jump and a backward takeoff for the Axel — it’s considered to be “cheated” (ISU’s term, not mine) and is subject to a downgrade. Pre-rotation can only be assessed by reviewing a jump at normal speed, unlike under-rotation.

PR gets discussed often, and I’d guess it’s not because fans don’t understand that all jumps carry inherent PR — but that when you combine excessive PR (i.e., PR beyond what’s considered good technique and/or up to and past 180 degrees) with URs, especially borderline URs and uncalled URs... there’s what’s lacking on the landing and what was lacking at takeoff, but only the landing is evaluated, so the punishment (if a UR call is even made) doesn’t reflect the weakness of the jump. Someone with minimal PR and someone with 179 degrees PR will receive the same punishment if they both are called for URing a jump, which seems inherently bogus. And a high degree of PR is generally correlated to issues in technique that should lower GOE for “poor takeoff” — “full blade assist” instead of pure pick assistance on toe jumps, for example, almost inevitably leads to greater PR, even if not the full 180 degrees worth required for a downgrade. There’s an argument that TPs should call a jump based on what’s performed rather than intended (so a flutz would be called as a flip, with all the risk of Zayaking that entails, and a Lutz that turns into a loop would be called a loop), but that’s both unlikely to happen and largely impossible to implement.

As it stands, the system is set up to closely scrutinize issues in rotation that occur on the landing of a jump, and while there’s technically a remedy for pre-rotation, it’s almost never applied. There’s also the issue of what you find to be a greater flaw — personally, excessively PR’d jumps bother me more than landings that are exactly 90 degrees short, as excessively PR’d jumps tend to be smaller and, when not also UR’d, heavily reliant on rotational speed to complete the revolutions in air. A number of issues that correlate with above-average PR could be classified as “poor technique” and receive negative GOE for “poor takeoff,” but as of now, they aren’t, and since the TP is limited in assessing and calling PR, URs are what are called, not PR.

I would like to see ISU define PR by jump type, so that rather than the blanket 180 degree rule, the “expected” or “natural” PR value per jump is defined, with judges and TPs given methods to deduct for PR in the same way as UR (since judges have a negative GOE bullet for URs not called by the TP). And both should be subject to reduction in BV. If a jump is both excessively PR’d and UR’d, then it should be downgraded, as the jump is lacking rotation of more than half at that point.

I find it odd that there’s so much focus on URs when URs can happen to anyone, and aren’t uncommon if a jump doesn’t go as planned, whereas PR occurs before the skater leaves the ice and is a more deliberate evasion of the rules. There’s a tendency for “but pre-rotation!” and “full blade assistance” to be thrown out as almost buzzwords, but that doesn’t mean they aren’t genuine issues the ISU needs to address to reward the great jumps differently from the “decent at best” ones. But as things stand, we’re a long way from that happening.

NymphyNymphy said:

Shoma I can understand but Yuzu and Nathan? I'm not sure about that.

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I'm just using this chart from last year and comparing to Trusova's 62.9cm 4T: https://cdn.tribuna.com/fetch/?url=.../29/08bad3080cef81ee2e9580f514bbc29e-full.png

Sugar Coated said:

Is there any data on senior ladies? I’d be interested in ladies height and rotation velocity over time (from juniors to seniors). This info may be useful to predict who is more likely to have long term success with certain jumps as they transition to seniors. I have a feeling someone like Sherbakova might have more difficulty maintaining her quads as she seems to depend on very fast rotation speed.

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So the thing is, Shcherbakova jumps a 39cm 3Lutz but jumps a 53cm 4Lutz. That would imply that she has plenty of jump height in the tank to spare.