The diffusion of a particle in a two-dimensional triangular periodic potential is studied within the strong-collision model by molecular dynamics simulations. In this model, the particle suffers well-separated collisions of frequency eta with the substrate. We calculate the long-jump probability depending on eta and on the barrier height. We treat the case in which the saddles of the potential are wider than the minima, obtaining that it is even more effective in hindering long jumps than a potential with narrow saddles on a square lattice. We show that an anomalous dependence of the diffusion coefficient D on eta holds in the low eta limit. (C) 2014 Elsevier B.V. All rights reserved.