A crossover from dilute to semidilute regimes of lattice chains has been simulated with the help of a novel method. A Monte Carlo step tries to replace an existing chain by a new chain constructed in biased, excluded volume avoiding steps. Reserve bifurcations are allocated at small intervals of steps and after each interval a selective lottery restores an effectively nonbiased probability distribution. If a construction fails the selection at an nth step, it falls back to n - 1, n - 2, until it "rebounds" from an unutilized bifurcation. Selection on the go combined with a freedom to rebound, make the construction self-corrective; the principle may have a broad applicability.