5 reasons why Serena Williams is tennis' definitive GOAT

4. Played all types of rivals and won

Williams, pictured with the ‘Ninja’, Agnieszka Radwanska

Big servers? Serena Williams has defeated them. Tactical players? She’s beaten them too. As swiftly as she can return the serves of a Petra Kvitova or her own older sister, former No.1 Venus Williams, Serena can also outfox the strategic Agnieszka Radwanska, whose sneak attacks have earned her the nickname of ‘Ninja’.

She may have seen upsets, but Serena Williams has always held her own against opponents on clay, hard court, grass, you name it. It does not matter what their specific ‘weapons’ are or where they target the ball – the American ace is always in the fight, even if she does not always win.