Jessica Pegula revealed Friday the secret behind her run to the fourth round of the Australian Open—spending every night down the casino. The American 21st seed faces Maria Sakkari on Sunday in Melbourne and will be plotting the Greek fifth seed’s downfall over a game or two of blackjack.

“Honestly, I have been going to the casino a lot,” Pegula, 27, said after a 7-6 (7/3), 6-2 victory over Spain’s Nuria Parrizas-Diaz. “No, literally, I think I have been six times. I was going every single night. It’s good because it got me kind of thinking about strategy and all this stuff, but at the same time, it would kill some time and relax me.”