Calculating COI%

[Dj01122024]

Ok, so I understand what COI% means. I also understand that at this time there are no negative effects in game. What I want to know is how to calculate it. Obviously when you breed a 0% COI horse to any other horse, it will lower that other horse's COI% assuming it is not already 0, and that the horses are not related. But it gets more complicated when you have, say, a 43.67% COI horse and a 60.15% COI horse. How would I calculate that? If I bred those two horses, would the COI% go up or down, assuming the horses were not related to each other? And assuming that I was to breed 2 unrelated horses with 100% COI, shouldn't the percentage still go down?

I'm trying to pinpoint the ins and outs of this, as I am trying to lower the COI% in my competition horses so that when and if COI% starts having negative or positive effects, I'm starting out low and can raise it as necessary.

[BlackOak2]

Ok, so I understand what COI% means. I also understand that at this time there are no negative effects in game. What I want to know is how to calculate it. Obviously when you breed a 0% COI horse to any other horse, it will lower that other horse's COI% assuming it is not already 0, and that the horses are not related. But it gets more complicated when you have, say, a 43.67% COI horse and a 60.15% COI horse. How would I calculate that? If I bred those two horses, would the COI% go up or down, assuming the horses were not related to each other? And assuming that I was to breed 2 unrelated horses with 100% COI, shouldn't the percentage still go down?

I'm trying to pinpoint the ins and outs of this, as I am trying to lower the COI% in my competition horses so that when and if COI% starts having negative or positive effects, I'm starting out low and can raise it as necessary.

Here's the current formula that the game uses.

https://www.bloodlines.net/highflyer/co ... ith%20each

To answer you directly.
Two unrelated horses should have a percentage reduction, but may end up being somewhere between the two COI's; so if your mare is 99% and your stallion is 40%, it may be much closer to 50 or 60%.

Likewise, any horse that +100% coi and it's bred to a 0% COI, it may still show the foals as +100% coi.

https://www.horseworldonline.net/horse/profile/4294827 This horse is the offspring between a +100% COI and a 0% COI set of parents. If you open the pedigree of that +100% COI parent, you will see that one of those is another +100% parent as well. So this +100% COI is only just over (somewhere) that 100%. We are capped at 200% COI, although we can only see the +100%. So any horse in-game will be NO MORE THAN 200% COI. Every horse that is +100% COI will have a maximum chance of breeding down below 100% COI, however I haven't done an experiment to see how long yet. Nobody else has yet posted any info on that end as well yet.

[Dj01122024]

So realistically speaking, once I start taking the steps to lower COI, then it may take a few generations to see a difference when the starting parent's COI is +100%, even if the other parent has a COI of 0%?

[Argent]

https://www.horseworldonline.net/horse/profile/4294827 This horse is the offspring between a +100% COI and a 0% COI set of parents. If you open the pedigree of that +100% COI parent, you will see that one of those is another +100% parent as well. So this +100% COI is only just over (somewhere) that 100%. We are capped at 200% COI, although we can only see the +100%. So any horse in-game will be NO MORE THAN 200% COI. Every horse that is +100% COI will have a maximum chance of breeding down below 100% COI, however I haven't done an experiment to see how long yet. Nobody else has yet posted any info on that end as well yet.

COI reduction over time
https://www.horseworldonline.net/horse/profile/4262876

[BlackOak2]

https://www.horseworldonline.net/horse/profile/4294827 This horse is the offspring between a +100% COI and a 0% COI set of parents. If you open the pedigree of that +100% COI parent, you will see that one of those is another +100% parent as well. So this +100% COI is only just over (somewhere) that 100%. We are capped at 200% COI, although we can only see the +100%. So any horse in-game will be NO MORE THAN 200% COI. Every horse that is +100% COI will have a maximum chance of breeding down below 100% COI, however I haven't done an experiment to see how long yet. Nobody else has yet posted any info on that end as well yet.

COI reduction over time
https://www.horseworldonline.net/horse/profile/4262876

That shows part of the equation. Thank you for sharing.

Do you have a second one where a horse with max COI (+200), assumed, is bred down throughout with 0% COI partners that you can share also? Or are you assuming that horse is already a +200 COI?

So realistically speaking, once I start taking the steps to lower COI, then it may take a few generations to see a difference when the starting parent's COI is +100%, even if the other parent has a COI of 0%?

The above horse shows the breeding that appears to take six generations to go from over 100% to almost 0%, using 0% COI partners.

I'd say a single generation, but it might take two before you see the +100% change (or three, as you're suspecting). That horse above is a fairly excellent example and may also cover the +200 COI as well. There are a number of reoccurring horses in that pedigree.

If you use unrelated partners but that also have their own COI, it's assumed to take longer and that path is based wholly on the COI of either parent and of each generation.

[Argent]

The original 100+ COI horse isn’t mine, so I don’t know what number is hiding behind the cut off, but you can loosely assume a 50% reduction each generation, so it was probably close to 200%

[Argent]

And then COI will haunt you for generations before getting back to zero: https://www.horseworldonline.net/horse/profile/13342

[BlackOak2]

-_- Unfortunately, the new formula does appear to work that way, yes.