Best plays today IMO, parlayed or whatever.
Kei for all the reasons everyone has mentioned. Isner has been a great story but all his opponents had recently demonstrated noticeable flaws, which Kei has not.
Halep entirely capable of destroying Serena on an off day, but I think that day was yesterday. I expect the GOAT to be more focused going up against the last person to beat her in front of her home crowd.
Also took CSN but less confident.