The classical approach to flood frequency analysis is hampered by the lack of sufficient data. This is especially true when the interest is in estimates of events of large return period (hundred years or more). In many countries, economical constraints force environmental agencies to reduce the gauging network, a factor that certainly does not help hydrologists. Regional analyses can to some extent compensate for the lack of temporal data, but introduce a spatial dimension which is not always well understood. Classical flood frequency analysis, be it at-site or regional, has been critized for lacking balance, for putting too much emphasis on mathematical rigor while completely neglecting the understanding of the physical factors that cause flood events. A critical discussion on this aspect is provided by Klemes [1993], who states that ``if more light is to be shed on the probabilities of hydrological extremes, then it will have to come from more information on the physics of the phenomena involved, not from more mathematics.'' This is a fact which is difficult to argue against. Regionalization, in particular the identification of the physical or meteorological catchment characteristics that cause similarity in flood response, is a step in the right direction. Hopefully, future research on flood frequency analysis will find a more appropriate mean course between statistical theory and physics of floods.