Tl;dr: Serena is the GOAT.
Serena Williams faces Simona Halep in the Australian Open quarter-final—her 13th in Melbourne and her 54th overall. But before the tournament started, Jeff Sackmann aka Tennis Abstract delved into a controversial topic: comparing Serena’s grand slam haul with Margaret Court’s.
Let’s set aside the off-court stuff and work this out. The pro-Court case is simple: 24 is greater than 23, and you have to evaluate players relative to their own eras. The pro-Serena side is equally straightforward: 11 of Court’s 24 titles came in Australia, before Melbourne was a mandatory tour stop. Regardless of the era, Court’s home event was weaker back then.
I’ve already spoilt the outcome but if you want to see how Jeff got to that conclusion from a mathematical perspective, read the post on the TennisAbstract blog.