@Craig_Martin_Herd_Of wrote:
So I’m new to B - I probably break some of your analysis, I won a few C races on my way up. I went from being not competitive, to suddenly being competitive, to bumping the top of category in a few weeks - then I wanted to finish the series I was in. I didn’t cruise, but I did avoid shorter races for a few weeks.
No, I don’t think you’re breaking the analysis. If you’re willing to work hard, then you can be competitive for a brief while as you are on the cusp of getting upgraded. A sandbagger you just cannot beat, but a cruiser is not impossible to beat. It’s just that he has the upper hand, which on average will show in his results. But since you’re not monitoring your 20 min W/kg like he is (or you’d be a cruiser) then sooner or later, if your fitness doesn’t deteriorate, you’ll go over limits and get upgraded. The cruiser can be around for years in the same cat. I could show you examples, but I won’t. Like I have said before, this isn’t about individuals doing a bad thing. It’s about a bad system doing bad things to people.
You bring up another important point that I haven’t mentioned myself although I’m painfully aware of it. Another of the many flaws of the W/kg system - distance! In a way you can only be competitive in a cat (unless you are cruising) on a certain distance. The stupid W/kg system doesn’t take distance into account. Typically, results-based cat systems do weigh in distance. The points scheme for races in US cycling go deeper down the classification in longer races and in x-country skiing it’s accounted for via finish time separation (which of course varies with distance).
I’m sure many Zwifters have made the mistake of participating in sprint races while they were on top of a cat with regards to standard 40’ish min races. In a sprint race you can of course do W/kg that wouldn’t be achievable in a 40 min race and so you get upgraded earlier. Which means you are actually below the W/kg floor in your new cat in a 40’ish min race! It’s just so dumb…
@Gordon_Rhino-Racing wrote:
This is a wrong assumption. Given the the figures you suggest above i think the lighter rider would easily win that race. Would be good to see any data on this if you have it?
Well, I didn’t provide data or calculations for the single theoretical case with the heavier 300W rider against the lighter 275W rider. It’s just an arbitrary example to illustrate a point. But I don’t actually think the lighter rider would win in a TT where both riders put out ERG like even Watts. The lighter rider will be faster than a rider at 275W with the same weight as the 300W guy. This is because the lighter rider - as I discovered only recently although others knew already - does suffer less air resistance. But this difference in air resistance is very small. I could be wrong, but I highly doubt it could account for a whopping 25W in this scenario.
What I did provide data for was that riders with a weight higher than the race average podium more than the average weight rider. And this is an undisputable fact. What the results say, literally, is that I could sample 40 new races a thousand times and the result would be the same every time, i.e. heavier riders do have an advantage in C and B (and of course D although I didn’t include them).
What I didn’t discuss (and didn’t study) was that while there is some sort of correlation between weight and win rate, it is not linear. You don’t win more the heavier you get obviously. Rather, I’m guessing it’s something like this, if we transpose a graph of win probability to weight on top a distribution chart over racer weights:
So on the X-axis we have rider weight. And on the Y-axis we have both n = the total no of racers we look at, and also p = win probability.
So weight is a typical normally distributed human feature, and A here is the average weight of racers in a certain cat. B is the average weight of winners in the same cat who of course also have the highest win probability. So most racers will be fairly close to the avg weight. But most winners actually weigh a bit more than the avg racer weight. At some point the additional weight will start to damage win probability though and so p starts to drop off. Why is that? You have it figured out already but maybe others don’t. It’s because of this:
So the first rider is a bigger and heavier guy than the second rider. No 2 gets a wee bit less air resistance in Zwift due to his lower weight and, possibly, shorter height. But it doesn’t make up for No 1’s bigger muscle volume. No 1 can push much higher Watts at 3.2 W/kg than the No 2 on the flattish (like the standard Zwift race) and that will translate to higher speeds and thus more wins on average. The key thing here is that both of them are capped at 3.2 W/kg or they get a DQ. So the lighter rider can’t compensate with a higher W/kg and win.
The No 3 guy, I would say, is past the point where his higher weight gives him an advantage. The two first riders have roughly the same body fat percentage, so bigger size = more muscle. But No 3 has a higher body fat percentage than both the others and excess body fat doesn’t do you much good in a hard 40 min race in Zwift (I can attest to that). And so the win probability curve starts to drop off beyond a certain point because people only grow so tall and thus they only get so heavy, and beyond that any extra kg’s is body fat.
(The exception here, maybe, is that people who used to carry a lot of overweight and then lose it, working hard in Zwift, are often damn strong because their muscles used to have to carry that overweight around - they often come out of a weight loss like rockets in Zwift, a little reward for the struggle perhaps, well deserved.)
In your own example the lighter riders wins and shows a much higher W/kg. That’s great! Why would you want to rob him of the win by pasting a big fat DQ on his race result? Why even speculate whether he could still have won doing 3.8 W/kg? (I’m not so sure he would BTW.) That is the same as saying “Could he have won on ZP if he had cruised the race?” (4.1 is OK, I know, but you get it.) So yeah, you understand why I’m against the W/kg system. And I’m sure none of us would regret a move to a results-based ranking once it’s in place. It would be so worth it. There is nothing to lose, because the system we have is crap.
You’re absolutely right about the way the importance of weight changes as you rise in categories. You see it clearly in data. Even so, a higher than average weight in cat B, where people are clearly slimmer on average than in C or D, is an advantage. The results are there in my little study, no doubt about it. And then in cat A, where there is no performance ceiling, you have your muscle volume and your fitness, whatever it is, and only stand to gain from a weight loss, up to the point where it starts to hurt your performance of course.
@Phil_Waters wrote:
I race at Cat C and weigh in at 98kg - the norm for me is for to finish lower than most lighter riders with lower power output but higher w/kg.
But then you’re not on top of cat C, if there is still room for a higher W/kg! Once you are just below the 3.2 W/kg ceiling, then I assure you that you will have an advantage over lighter riders. They have no counter to you, none that wouldn’t result in a ZP DQ anyway.