We disclose a monovinylarene/conjugated diene block copolymer, comprising: (i) a random (conjugated diene_x/monovinylarene_y)_m block, wherein x is about 2.5 wt % to about 10 wt %, y is from about 90 wt % to about 97.5 wt %, and x+y is about 97.5 wt % to 100 wt %; and (ii) a (conjugated diene)_n block; wherein n is from about 20 wt % to about 30 wt %, m is from about 70 wt % to about 80 wt %, and m+n is from about 90 wt % to 100 wt %. We also disclose a method of forming the block copolymer and a method for fabricating an article from the block copolymer. The block copolymer typically exhibits a T_g at least about 10 C. less than the T_g of a reference polymer differing only in that x is about 0 wt % and y is about 100 wt %.