Hello,
I’d like to give a bit of analysis based on what I see on ZRS behavior, from my personal position that I think it’s not the one of an average outdoor cycling guy (good aerobic skills) but closer to a velodrome one (good anaerobic skills). I hope we’re all aligned on how ZRS sets each rider’s seed score: 5 mins power raw watts and WPK with some adjustments due to weight.
Now: 5 mins power gives you an indication on what is the maximum anaerobic capacity and the aerobic lactacid capacity of a rider. It means it totally forget about the aerobic capacity of a rider and that, except for top level riders or all-rounders, an individual is gifted with a good aerobic OR anaerobic system. So it means that overall your ZRS seed score is reliable as a starting point for very short races, but it could be totally misleading for races that last more than 15 mins, and this depends on your phenotype (aerobic/anaerobic). Usually cycling people is better at aerobic than at anaerobic skills since outdoor cycling is an endurance sport, so the largest part of Zwifters will have worst anaerobic skills and better aerobic ones. It means, their 5 mins power will be more aligned to their aerobic plateau because their power curve is more flat than for anaerobic people. In this case, ZRS will put them on a range, for most of Zwift races that are usually longer than 20 mins, where they could be competitive on their aerobic range.
Then if you’re lucky to be an “average outdoor cyclist” you’ll be in the right range for races where anaerobic phenotypes are not the favorite ones (so races that ends in less than 15 mins), so the most common type of races on Zwift. But if you’re an anaerobic phenotype (pure sprinter or “velodrome guy”), then you’ll be put too high for races where the aerobic skills matter more than the anaerobic ones, and so as an example you’ll be put in races where you’ll definitely challenge Cs or Bs even if your aerobic skills are definitely D. Unfortunately, I’m in this exact position. My ZRS is 334, but this is a good score for me for races with a duration lower than 15 mins. So I’m racing only short/very short crits, or Tiny Races where they’re flat (so I don’t have to recover too much in the very short amount of time between the races). Previously I was racing a lot of D races where I could win pretty easily (I’m currently 47th in cat D individual and 32nd in cat D ZPoints, but I’ve been top10 for some time) because of my sprinting skills, because the full race was not exhausting me since I could stay lower than Z4 and then push it all at the final sprint. It’s just a matter of knowing who you are and what is your skills, then to understand what is the good type of races where your score allows you to compete to your maximum level. Personally, with ZRS going on this way, I’ll stop racing more-than-20 mins races and just focus on the sprint ones. Then it’s a pity we don’t have a velodrome in Zwift where we could have velodrome races, but that’s it.
Now, would it be possible to make ZRS work for all type of races and phenotypes? To me, yes. It should just be a matter of having a ZRS score for each type of race, at least from the expected duration of the race standpoint. As an example, picking up my values for time frames from Zwift profile:
5 mins: 293
20 mins: 240
30 mins: 231
40 mins: 212
Given that Zwift is absolutely capable of calculating the expected total time for a route given a specific power, it’d be just a matter of setting the right ZRS per time frames based on raw watts or WPKs and then have people put in pens for races on specific routes using those values. Plain, simple. And given that is perfectly known where raw watts or WPK are decisive (it’s all written in Zwift dynamic model to calculate how to make your avatar behave in a specific scenario), it should not be an issue to know what type of ZRS (raw or WPK) to apply on a specific race (given the expected time to complete a route, it should be possible to understand if overall the WPKs will matter more than the raw watts or viceversa).
So, basically: not a single ZRS per player, but 2 ZRS per time frames (one with raw watts and one with WPKs), and then apply the right one given the event. It should not be rocket science. 10 times the ZRS scores you have today it should not be an issue in terms of data management. You’re already managing all the powers and WPKs, it’s just a matter of adding more granularity to ZRS and races to make things work better, not just for the average rider but for all riders. It should improve a lot the experience for riders like me, allowing me to race in long races as well, and to further improve the experience for average riders.