Probability of observing five transiting planets in the HIP 41378 system over the planets’ precession cycles. The unknown longitudes of node Ω_k of the planets in the sky plane are drawn from a uniform random distribution in an interval ΔΩ₀ common for all planets. For a given value of the range ΔΩ₀ (vertical axis), a histogram of the transit probability is built from 10⁶ realisations of the Lagrange–Laplace system (colour scale). A bin is coloured grey if no occurrence is found among our 10⁶ realisations.