Australian Open: So many Slam champs over past 2 years

FILE - In this Jan. 27, 2018, file photo, Denmark's Caroline Wozniacki celebrates after defeating Romania's Simona Halep in the women's singles final at the Australian Open tennis championships in Melbourne, Australia. Wozniacki will be defending a Slam title for the first time after winning in Melbourne a year ago. (AP Photo/Andy Brownbill, File)

When Serena Williams was at her best, there was never much doubt that she’d be the favorite at pretty much any tournament she entered. While she was off the tour becoming a mom, women’s tennis was as wide open as ever.