A recipe for short-word pseudo-anosovs

Given any generating set of any subgroup G of the mapping class group of a surface, we find an element f with word length bounded by a constant K depending only on the surface, and with the property that the minimal subsurface supporting a power of f is as large as possible for elements of G. In particular, if G contains a pseudo-Anosov map, we find one of word length at most K. We also find new examples of convex cocompact free subgroups of the mapping class group.