▁the ▁tour ▁with ▁ 5 3 0 . ▁Ke ys ▁could ▁serve ▁at ▁more ▁than ▁ ▁when ▁she ▁was ▁ 1 4 , ▁and ▁was ▁clock ed ▁at ▁up ▁to ▁ ▁on ▁the ▁road ▁to ▁her ▁first ▁W TA ▁title ▁in ▁ 2 0 1 4 . ▁Although ▁that ▁serve ▁is ▁not ▁recognized ▁because ▁there ▁was ▁no ▁official ▁serve ▁speed ▁data ▁at ▁the ▁tournament , ▁the ▁W TA ▁has ▁recorded ▁her ▁serving ▁at ▁ ▁at ▁the ▁US ▁Open , ▁which ▁was ▁good ▁for ▁the ▁fifth ▁fast est ▁serve ▁in ▁ 2 0 1 5 . ▁ ▁On ▁multiple ▁occasions , ▁Ke ys ▁has ▁been ▁recorded ▁hitting ▁ground st ro kes ▁at ▁spe eds ▁that ▁are ▁compar able ▁to , ▁if ▁not ▁faster ▁than ▁the ▁top ▁men ' s ▁tennis ▁players . ▁At ▁the ▁ 2 0 1 4 ▁French ▁Open , ▁Ke ys ▁had ▁the ▁fast est ▁average ▁ground stroke ▁speed ▁of ▁any ▁player ▁at ▁. ▁For ▁comparison , ▁Nov ak ▁Dj ok ov ic ▁had ▁the ▁fast est ▁ground st ro kes ▁on ▁the ▁men ' s ▁side ▁with ▁an ▁average ▁speed ▁of ▁. ▁The ▁Game ▁Ins ight ▁Group ▁analyz ed ▁Australian ▁Open ▁data ▁over ▁a ▁five - year ▁period ▁from ▁ 2 0 1 2 ▁to ▁ 2 0 1 6 ▁and ▁found ▁that ▁Ke ys ▁had ▁the ▁second - fast est ▁average ▁fore hand ▁and ▁back hand ▁spe eds ▁of ▁all ▁players . ▁Her ▁ ▁fore hand s ▁tra iled ▁only ▁Tom áš ▁B erd ych , ▁and ▁her ▁