Difference between formulas and simulations. Plots show the differences Δ between the proportion of excess sequencing predicted under the parking distribution (R _parking) and the proportion of excess sequencing observed in (A) simulations in which the seed clones and walking clones are chosen from a randomly distributed library (R _sim) and (B) simulations in which seed clones are chosen from a randomly distributed library, but walking steps are then made under the ACO assumption (R _sim,ACO). Results are shown for various values ofd and θ. (■) d = 10; (⋄)d = 15; (○) d = 25; (▵)d = 50; (gray ▿) d = ∞.