How does the Destiny Knot change the odds?

With a Destiny Knot, five of the six IV slots are inherited from the combined parents, so any single owned target stat has a five-in-six chance of being passed down. Without it, only three IVs are inherited, dropping each owned stat to a three-in-six chance.

What happens to a stat no parent owns?

If neither parent carries a perfect value for a target stat, the offspring has to roll it randomly. A perfect 31 IV comes up only one time in thirty-two, which is why owned parent stats matter so much for the overall odds.

How does the Everstone affect nature?

An Everstone held by a parent passes that parent's nature to the offspring with near certainty, which the model treats as one hundred percent. Without one, the nature is random at one in twenty-five, multiplying into the overall per-egg odds.

What do the 50, 90, and 99 percent egg counts mean?

They use the cumulative formula one minus the chance of failure raised to the number of eggs. The 90 percent figure, for example, is how many eggs you need to hatch so that there is a ninety percent chance at least one of them meets every condition.

Is reaching the expected egg count a guarantee?

No. The expected number of eggs is one divided by the per-egg odds, but breeding is random. At exactly the expected count you still have only roughly a sixty-three percent chance of success, which is why the cumulative confidence figures are more useful for planning.

Destiny 2 Breeding & IV Calculator

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The Breeding & IV Calculator estimates how hard it will be to hatch an offspring with the exact stats and nature you want. It combines IV inheritance odds with held-item effects so you know the realistic number of eggs before you start the grind.

How it works

The model treats each desired stat independently. If a parent owns a target stat, the offspring inherits it with the per-slot inheritance probability; if not, it must be rolled randomly:

P(targets) = inheritProb^owned  x  (1/32)^notOwned
inheritProb = 5/6 with Destiny Knot, 3/6 without

Nature is then layered on: an Everstone effectively fixes it (treated as 1), otherwise it is 1/25. The combined per-egg chance is the product, and the expected eggs is its reciprocal.

To plan a session, the cumulative formula solves for the egg count at a target confidence:

eggs = ceil( ln(1 - confidence) / ln(1 - perEggChance) )

Tips and example

Want five perfect IVs where parents already cover four, with a Destiny Knot and a specific nature via Everstone? The four owned stats each pass at 5/6, the fifth rolls at 1/32, and nature is fixed — the calculator multiplies these into a single per-egg chance and shows you that you may need dozens of eggs for 90 percent confidence. Always breed with the most owned target stats possible; each owned stat dramatically shortens the grind.