Pack Dynamics 4 - Phase 3 [January 2023]

Exactly. This was a PD4 Tiny Race a couple of weeks ago. Near the start I slipped back to about 2/3 of the way back, but managed to pull it back.
Wouldn’t want to fall back any further than this…

Looking at the video again, I was in the draft almost the whole time and had no red numbers at all. No churning on the front. No difficulty staying off the front :rofl:
PD4 seems to working fine from my point of view. :grinning:

Except it didn’t make me win!

Well raced!

As far as I understand, we don’t get red numbers in all the situations where we are auto-braked. I have only seen it in high-draft to low-draft situations at the front. It would be nice to see it every time to learn how to ride more efficiently.

I wonder if there have been any tweaks to PD4 lately? Maybe it has changed and my experiences are stale.

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I can make red number show without going to low draft.

Sprint into the back of the pack and stop pedalling suddenly and you get red numbers while still in full draft in the middle of the pack.

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I’m just referring to:

Question, why was reducing the draft benefit of a user advancing through the field never considered?

Another question, have you detailed the current criteria for being autobraked? Without red numbers and without it explained that it’s leaving it to people to guess when/why/how they’re being dropped from the field.

When will flashing red numbers be implemented outside of races? And for all circumstances where a user is being braked? Hard to get to know PD4 when how it’s working is hidden.

Edit: thanks Gerrie for moving my post from where it was appropriate to where it’s now redundant

I feel like I’m talking to myself here :-), but I really think some improvements could be made.
I raced the STAGE 1: COBBLE CRUSHER - R.G.V today and it ended up being an iTT for most:

No rest is to be found anywhere.
I was behind the front after the aqueduct by ca. 10-15m. Usually, the huge draft benefit from the pack makes it possible to get back on the descent. I got into the situation I described above where I got stuck behind a rider on my way to the front pack. It felt like the sticky draft, but much worse. I finally got back to the front and iTT’ed in. No one tried to go off the front. I guess no one had anything extra to give when the whole race felt like an iTT (no rest).

Chasing Tour 2023 opted in to PD4 for the series, next race this Sunday on Lutece Express (so, mostly flat - but now…perhaps breakaways?). Most of the time slots have 100+ riders now mass start - so widely varying power outputs. Will be interesting to see how it goes.

If I understand correctly, this would have required some power variation on your part as one of the auto-brake inputs. Without seeing some video of it with the Zwift HUD showing power it is hard to say why this happened, but if the description of auto-brake conditions is correct and you just kept steady non-zero power while descending I don’t think PD4 would have done a single thing different vs PD3

As a lightweight, an ITT during races or fast group rides has always being the case for me. Welcome to my world.


Is the PD 4, discusse in this thread, included in the recent game update and is it enabled for all kind of rides?

Changelog from latest game release:

  • Improved experience when riding in a pack with new pack dynamics

It certainly feels different, so I assume it is because of PD4/DD.

ITT’ing in a mass start race is no fun at all. Neither for you nor me.

EDIT: If we can get red numbers or something similar all the time we are auto-braked, it will be much more obvious when PD4 is behaving strangely and unexpectedly and we will be able to give more nuanced feedback.

One of the previous posts from David said the threshold was at a 3% reduction from your last 10s power. This is impossible to not trigger during a race. I haven’t seen any more recent comments laying out what sets off the brakes so don’t have anything else to go off of.

In other news if the negative effects seen in Kristian’s comments are from PD4 then we’re not at “just Makuri” for PD4 but maybe everywhere? Just in the zwift weekly races? All events?

zwifthacks indicates the crush the cobbles events are PD4-opt in

Is that race using PD4?


These are the rules that apply AFAIK:

Rules for the auto-braking

Auto-braking will be applied if:

  • The amount of draft savings exceeds a certain threshold (this threshold is variable according to the gradient. For instance, it is set at 38% for flat. These thresholds are configurable server side, but there is no point in detailing the values given that they are not visible for you in the HUD. Maybe something to improve in the future…)
  • AND your speeds exceeds the speed of the bike in front of you
  • AND your power drops below your last 10 sec. average power (signalling you are slowing/relaxing).
  • AND your power does NOT exceed X% above your last 10 sec. average power (currently X is set at 110%. It can be changed if needed).

So to put it in simple terms, if the system detects you are “relaxing” your power but your speed is above the rider in front in HIGH draft situations, it slows you down.

Other situations:

  • If you are travelling at a much higher speed then the rider(s) in front of you, you will never get auto braking. Currently the limit is set at 3km/h (it can be adjusted).

The two last ANDs are contradicting, so the actual logic is uncertain.

That’s the last I’d seen but it was months ago. Wondered if there was anything changed since. I’m confused about the last two though. Trigger 3: Power below last 10s avg. Trigger 4: Power not over 110% of your last 10s avg. Seems redundant.

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It might be that it should have been a AND (… OR …). :man_shrugging:

@DavidP Went silent about the changes at some point and it became hard to give constructive feedback in relation to the changes he made. I guess he has his reasons. It seems like he is satisfied with the current implementation and has better things to do.

COBBLE CRUSHER need to be homologation , it GC time base, wrong to mess with mid week. fyi @DavidP @James_Zwift

Not only it was considered, it was even tested and it’s one of the current system possible configurations :slight_smile: It was tested in a few test events a couple of months (or more :thinking: ) back.

Why was it not used or is currently not being used? Because it was not being effective in doing any relevant change. It was just too “mild”.

I can detail the criteria up to a certain point. More than that we reserve the right not to reveal it at the moment and also because some of the variables taken into consideration are not even visible in the HUD.

Essentially, you can get slowed down if:

  • your current draft is within certain ranges, mostly in the transition from medium to low draft. but not exclusively.
  • And, you are within half a bike length of the bike in front.
  • And, your speed is above the bike in front of you
  • And your power is reducing compared to your previous 10 sec. power. (the ranges can also vary on certain conditions it has to decrease more than 10% and it needs to go down by up to 70% in the most “aggressive” forms of slowdown).
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