▁back hand s ▁tra iled ▁only ▁Li ▁Na . ▁Out ▁of ▁just ▁her ▁fast est ▁ 1 % ▁of ▁sh ots , ▁Ke ys ▁hit ▁an ▁average ▁fore hand ▁at ▁, ▁which ▁was ▁stronger ▁than ▁L ley ton ▁H ew itt ▁and ▁close ▁to ▁David ▁Fer rer . ▁Her ▁fast est ▁back hand s ▁had ▁an ▁average ▁of ▁, ▁which ▁was ▁faster ▁than ▁that ▁of ▁Bernard ▁Tom ic ▁and ▁close ▁to ▁Nick ▁K yr g ios , ▁both ▁of ▁whom ▁have ▁a ▁reputation ▁for ▁being ▁able ▁to ▁hit ▁powerful ▁ground st ro kes . ▁ ▁Co aches ▁When ▁Ke ys ▁was ▁at ▁the ▁E vert ▁Tennis ▁Academy , ▁she ▁was ▁primarily ▁co ached ▁by ▁John ▁E vert . ▁She ▁also ▁worked ▁with ▁his ▁sister ▁Chris ▁E vert , ▁a ▁member ▁of ▁the ▁International ▁Tennis ▁Hall ▁of ▁Fame . ▁In ▁ 2 0 1 1 ▁after ▁six ▁years ▁at ▁the ▁a cademy , ▁Ke ys ▁switched ▁coach es ▁to ▁Adam ▁Pet erson , ▁who ▁was ▁assigned ▁to ▁work ▁with ▁her ▁through ▁the ▁U ST A . ▁Pet erson ▁is ▁better ▁known ▁as ▁a ▁long ▁time ▁coach ▁of ▁L inds ay ▁D aven port , ▁who ▁would ▁also ▁later ▁coach ▁Ke ys . ▁In ▁her ▁early ▁pro ▁career , ▁Ke ys ▁also ▁worked ▁with ▁two ▁other ▁U ST A ▁coach es , ▁Juan ▁Tod ero ▁and ▁Jay ▁Good ing , ▁who ▁helped ▁her ▁break ▁into ▁the ▁Top ▁ 5 0 ▁of ▁the ▁W TA ▁rank ings . ▁ ▁Before ▁the ▁start ▁of ▁the ▁ 2