a champagne type base for a molded polymeric container has an annular step immediately inside an annular contact ring . a push - up area is a central portion of the base immediately surrounding the container longitudinal axis . a transition region between the push - up area and the annular step provides for outstanding base stabilization . the transition region includes an upwardly arching surface extending between the annular step and the push - up area with a plurality of integrally molded , spaced apart , radially extending and downwardly projecting hollow ribs . each of the ribs has a lower curved surface extending substantially continuously from the push - up area to the inner margin of the annular step .