 The popularity of the Prince aluminum oversize had the side effect of popularizing rackets having other non-standard head sizes such as mid-size and mid-plus sizes .Fairly quickly, midsize frames began to become the most-used frames in the pro tours.Martina Navratilova popularized the midsize graphite racket, with her wins using the Yonex R-7, the first midsize graphite racket made by Yonex.