I’m pretty sure zFTP = CP but some confirmation would be great.
The answer is Yes and No.
Let me try to explain. There was some wrong information that was spread since the beginning of the CE system, that we are using CP, and so the CP term was adopted and used.
zFTP is calculated using a similar system as the classical CP. But because we have no way of knowing or guaranteeing which values of the curve are maximal, we have to analyse the curve to determine which values are maximal (or close) and adjust things accordingly to calculate the best fit for the regression. Therefore, mathematically zFTP is different than CP.
However the part of the answer that is Yes, zFTP = CP, is because the term was wrongly adopted since the beginning.
So ideally from here on in, it would be best we all call it zFTP (and that is the value that is used for category enforcement) and not CP.
I hope I’ve made things a bit more clear.
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I just don’t know what to say to be honest.
Good luck?
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i think you should add another 40 pages to your pdf james
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First slide:
“There was some wrong information that was spread since the beginning of the CE system, that we are using CP”
Subsequent slides. Every single piece of Zwift communication that has related to Category Enforcement referencing CP.
Final slide. Burning building meme, with Eddy Hoole tied to a chair in the corner.
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It would be more consistent to call it zCP and not zFTP. It seems that you are still doing a classic CP calculation, just selecting the points to fit based on extra analysis / best-fit to the curve. zFTP would be the right term if you copied what WKO does for its FTP estimate but that is a different underlying calculation.
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Thanks for the update @xflintx - and what is the transparency of this data be like? Will others be able to see mine so they know I’m racing honestly (I would want them too!)? And will race organisers have the ability to see this to help make community events as competitive as possible?
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Realized I forgot to mention that in the OP, so I edited it.
You will only be able to see your own information for the time being. No one can see yours and you cannot see others’.
That may change, though for the first pass that will be the case.
Is this just an elaborate ruse to stop us talking Eddie Hoole and known exploits being left open?
This CP inaccuracy, that was proliferated by zwift staff on an almost weekly basis… In all the open & honest comms no one thought, hang on this info might not be 100% accurate?
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I’m fine with you calling it zFTP. It will be relatable to casual riders.
I’m also pretty sure zFTP is simply replacement terminology for the CP value that you have been using for months. Also fine, but why oh why does everything have to be so obfuscated.
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Also fine, but why oh why does everything have to be so obfuscated.
Come on James, you couldnt be further from ‘new around here’ and have to ask that.
Zwwwiiiiiiiift.
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I actually think there’s some quality work going on in the developer dungeon on this topic. When it comes to comms though I reckon they’ve hired Prince Andrew’s advisor.
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It will be relatable to casual riders.
Exactly. Imagine that 90% of folks on Zwift know what FTP means. How many know CP or other advanced terms? If we would came up with something like zCP, the amount of confusion and questions about it would be greater. Not only on the CE topic, but others because we hope to use it for other features.
Also fine, but why oh why does everything have to be so obfuscated.
That’s probably our fault in the way the comms between technical staff and who handles forum communication was not the best.
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Yes. Thank you.
Don’t overthink it. Transparency is key.
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Loving the development put into this, it is a much needed addition to CE. I would recommend to make the FAQ consistent with the values you can actually look up on your profile. For example the 4.2 wkg or 250W limit. It can be zFTP but then name it such in the table. Or Critical Power as the current header uses, but then one of the CP durations on the profile should match what you use for the CE limit. Could be 10, 20 or 30 min whichever you feel as most appropriate. This is all from a User Experience point of view. There is also some unclarity in the VO2max specification (edit for clarification: the VO2 term is used as it’s own criteria, but also in combination with the MAP where it uses a different threshold value), so would be great if this could all be ironed out.
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I do agree calling it zFTP is more relatable for most than zCP, though I’m sure you’ll get questions about it vs. other FTP estimates! On the same note, maybe rename the section of the 5s to 30 minute table from “Critical Power” to simply “Recent best efforts”.
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I think they might be calculated points on a curve though rather than best efforts? Not 100% sure. If they are best efforts, it should definitely be renamed
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I think they might be calculated points on a curve though rather than best efforts?
They are the best efforts within the last 60 days. Sure it can be renamed. There is so much confusion around this.
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Luckily, you probably have the tools and channels to fix that…