Zezo forum: Sail selection issue ?

Sail selection issue ?

Post by jfloviou | 2020-12-15 | 00:23:46

Hello,

I'm seeing strange sails selection in zezo. Haven't seen the issue before.
(i'm full pack):
TWS 30.2
TWA 140
Sail selection HG ! (should be staysail)

Any recent change that could explain this new behavior?

10 Comments

Post by jfloviou | 2020-12-15 | 00:42:52

Oups, my bad, in fact both sails perform the same. It's a bit misleading

Post by toxcct | 2020-12-15 | 00:49:11

No way the staysail overtakes on the Heavy gennaker in these conditions.

Check this, and play with the checkboxes :
http://toxcct.free.fr/polars/?race_id=470.1&twa=140&tws=30.2&light=false&reach=false&heavy=true&foil=false&hull=false&utm_source=zezo.org

Post by zezo | 2020-12-15 | 08:37:56

I think jfloviou is talking about race_id=440

Post by toxcct | 2020-12-15 | 09:39:19

Oh god, sorry, you're right.

Yes, on the polars chart, we can see very well that both sails overlap.
Both sails have a speed (2 digits rounded though) of 21.06 knots.

So there is a risk that in the long term that the wrong sail is selected if the sigma between the 2 is too small.
Maybe someone else can explain about the "autoSailChangeTolerance" and the "badSailTolerance" polars properties and how they behave in VR ?

Post by MidnightFoiler | 2020-12-15 | 11:37:08

Yes, and I notice that zezo over the last day seems to be applying penalties for changes between Staysail and HG presumably due to small differences in rounding or some such. You could then see the dot on the green line clearly ahead of the isochrone at 150 twa.

Oddly though you could route to a point on the 150 twa line and it would then seem to put the isochrone closer to where it should be.

Post by YourMomSA | 2020-12-15 | 15:33:13

Per the info I got from M63 in the FAQ here:

http://zezo.org/forum.pl?tid=7877

Autosails don't change the sail until the new sail is faster than the old by at least 0.3%. So in a situation like this, you might see the change being recommended in multiple places, including the UI, Zezo, and the polars, before Autosails will actually change it.

Post by jfloviou | 2020-12-15 | 15:59:54

- autoSailChangeTolerance: 1.003 : Les voiles se changent quand tu as l'autosail si l'�cart entre les deux voiles d�passe 3/1000
=> Under autosail, sails are changed automatically when the speed with current sail is 1.003 slower than another (better) sail

- badSailTolerance: 1.01 : Le message mauvaise voile s'affiche si l'�cart entre la voile la plus rapide et celle que tu as d�passe 1%
=> The "bad sail" message appears when there is a better sail giving a speed 1,001 better than the current one

Post by Shelisteam | 2020-12-30 | 12:53:34

My problem is change the course +-1 and the game warn me about pennalty of the monouvere. Sails remains same before and after changing (staysail) - what is wrong.

And second question: can I switch off automatic sail change in full pack?
Tom

Post by karriv | 2020-12-31 | 06:40:44

In my experience the client warns about the maneuver penalty quite randomly and you can check either from the polar or the game interface whether the sail actually would be changed. It could be that the one degree change triggers a sail change, in many cases not.

The answer to the second question is a simple no.

Post by Shelisteam | 2020-12-31 | 12:20:03

From the polar changing the sails is not needed before and after same sail. But the game still warn me about penalty. In Dachboard no messege manouvere Yes. Hmmm?