▁Her ▁match ▁losses ▁are ▁often ▁due ▁to ▁her ▁oppon ents ▁prov oking ▁her ▁into ▁hitting ▁too ▁many ▁un for ced ▁errors ▁while ▁she ▁is ▁aim ing ▁for ▁w inners . ▁ ▁Although ▁Ke ys ▁pre fers ▁playing ▁on ▁hard ▁courts , ▁where ▁she ▁reached ▁her ▁first ▁Grand ▁S lam ▁final ▁and ▁won ▁her ▁first ▁Premier ▁ 5 ▁title , ▁she ▁has ▁had ▁success ▁on ▁all ▁three ▁main ▁surfaces ▁used ▁on ▁tour . ▁Two ▁out ▁of ▁her ▁five ▁W TA ▁titles ▁have ▁come ▁on ▁grass ▁courts . ▁Her ▁least ▁favorite ▁surface ▁is ▁cl ay , ▁which ▁is ▁typically ▁regarded ▁as ▁too ▁slow ▁to ▁suit ▁players ▁like ▁Ke ys ▁whose ▁style ▁revol ves ▁around ▁hitting ▁with ▁power . ▁Non eth eless , ▁she ▁has ▁won ▁one ▁title ▁on ▁cl ay ▁at ▁the ▁ 2 0 1 9 ▁Char l eston ▁Open , ▁reached ▁one ▁Premier ▁ 5 ▁final ▁on ▁cl ay , ▁and ▁also ▁made ▁it ▁to ▁the ▁semif inals ▁at ▁the ▁French ▁Open . ▁ ▁Ke ys ▁uses ▁her ▁strong ▁serve ▁to ▁domin ate ▁her ▁service ▁games . ▁In ▁ 2 0 1 6 , ▁she ▁finished ▁third ▁in ▁percentage ▁of ▁points ▁won ▁on ▁serve ▁behind ▁only ▁Ser ena ▁Williams ▁and ▁Victoria ▁Az aren ka , ▁among ▁all ▁players ▁with ▁at ▁least ▁ten ▁tour - level ▁matches . ▁That ▁same ▁year , ▁she ▁also ▁hit ▁the ▁third - most ▁a ces ▁with ▁ 3 0 0 , ▁trailing ▁Ser ena ▁who ▁had ▁ 3 2 4 ▁and ▁Pl í š k ová ▁who ▁led