How are inherited stats chosen?

The game randomly inherits a fixed number of the six stats from the parents. The tool models this as choosing that many stat slots uniformly at random, and counts a slot as perfect only if a parent already had a perfect IV there.

Why does an inheritance item help so much?

Raising inherited stats from three to five out of six dramatically increases the chance that the perfect parent stats are among those passed down. The tool shows this directly — five inherited stats can lift perfect-egg odds by an order of magnitude.

How is expected attempts calculated?

If a single egg meets your target with probability p, the expected number of eggs is 1 divided by p, the mean of a geometric distribution. The tool rounds this up to a whole number of hatches for planning.

What is the hypergeometric model here?

Inheriting k of 6 stats and asking how many of the perfect-parent stats land among them is exactly the hypergeometric distribution. The tool computes it with binomial coefficients, no simulation, so the odds are exact.

Does nature or move inheritance affect this?

No. This tool focuses on perfect-IV inheritance, which is the slowest part of breeding a flawless specimen. Nature can be locked with a separate item and is independent of the IV odds shown here.

Monster Hunter Breeding & IV Calculator

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Breeding a flawless specimen can take dozens of eggs if you go in blind. This calculator models the standard inheritance system — a fixed number of stats passed from the parents — and tells you the exact probability that a single egg hits your perfect-stat target, plus how many eggs you should expect to hatch.

How it works

If parents collectively own p perfect stats out of six, the offspring inherits k random stats. The chance that at least t of the inherited stats are perfect follows the hypergeometric distribution:

P(X = x) = C(p, x) × C(6 − p, k − x) / C(6, k)
P(X ≥ t) = Σ over x ≥ t

Expected eggs to hit the target is one over that probability:

expected attempts = 1 / P(X ≥ t)

Example and tips

With four perfect parent stats and three inherited stats, the chance an egg has at least three perfect IVs is modest, so you may hatch many. Switch to five inherited stats (an inheritance item) and the same target becomes far more likely, cutting expected attempts sharply. Always breed up: use your best offspring as the next parent so the perfect-stat count climbs each generation.