▁fore hand ▁and ▁back hand ▁sides . ▁Ke ys ' s ▁junior ▁coach ▁Chris ▁E vert ▁compared ▁her ▁level ▁of ▁power ▁at ▁ 1 8 ▁years ▁old ▁to ▁that ▁of ▁Ser ena ▁Williams , ▁saying ▁" I ▁can ▁almost ▁say ▁she ▁almost ▁matches ▁Ser ena ▁[ Will iams '] ▁serve ▁as ▁far ▁as ▁power . ▁Out ▁of ▁all ▁the ▁players ▁out ▁there , ▁she ▁comes ▁the ▁closest ▁to ▁Ser ena ' s ▁serve . ▁The ▁power ▁off ▁both ▁sides ▁is ▁trem end ous ▁for ▁someone ▁that ▁young ." ▁Ke ys ▁is ▁particularly ▁known ▁for ▁hitting ▁strong ▁fore hand ▁ground st ro kes . ▁Form er ▁world ▁No . ▁ 1 ▁Kar ol ína ▁Pl í š k ová , ▁who ▁also ▁has ▁an ▁el ite ▁fore hand , ▁and ▁ 2 0 1 7 ▁US ▁Open ▁champion ▁Slo ane ▁Steph ens ▁have ▁both ▁said ▁that ▁Ke ys ▁has ▁the ▁best ▁fore hand ▁in ▁the ▁game . ▁ ▁Ke ys ▁is ▁an ▁ag gress ive ▁bas el iner . ▁She ▁does ▁not ▁go ▁to ▁the ▁net ▁too ▁often , ▁instead ▁re lying ▁on ▁her ▁power ▁to ▁hit ▁fore hand ▁and ▁back hand ▁w inners ▁to ▁end ▁points . ▁The ▁Ag gression ▁Sc ore ▁metric , ▁which ▁measures ▁a ▁player ' s ▁ag gression ▁based ▁on ▁how ▁quickly ▁they ▁finish ▁points , ▁r ated ▁Ke ys ▁among ▁the ▁top ▁ 1 0 % ▁of ▁all ▁players . ▁Ke ys ' s ▁biggest ▁weak ness ▁is ▁her ▁in ability ▁to ▁control ▁her ▁power ▁at ▁times .