Lateral projection as a possible explanation of the nontrivial boundary dependence of the Casimir force

We find the lateral projection of the Casimir force for a configuration of a sphere above a corrugated plate. This force tends to change the sphere position in the direction of the nearest corrugation maximum. The probability distribution describing different positions of a sphere above a corrugated plate, which is fitted well with experimental data demonstrating the nontrivial boundary dependence of the Casimir force, is suggested.