American Madison Keys, 24, aims for her second straight French Open semifinal berth when she faces Australian Ashleigh Barty, 23, on Wednesday. The must-see quarterfinal matching rising stars begins at 8 a.m. ET from Roland Garros. Seeded 14th, Keys advanced Monday with a straight-set win and has now made the quarterfinals in five of her last seven majors. Barty, the No. 8 seed, is coming off a three-set victory over Sofia Kenin and will appear in her second consecutive Grand Slam quarterfinal. Keys and Barty split their two previous head-to-head matches. Bookmakers list Barty as a -178 favorite (risk $178 to win $100) in the latest Keys vs. Barty odds, with Keys getting +150 (risk $100 to win $150) as the underdog. Barty is favored by 2.5 on the “game spread,” and the over-under for total games is 23. Before you make any Keys vs. Barty picks or 2019 French Open predictions, you’ll want to see what Gavin Mair has to say, given the streak he’s on.

Mair is the international women’s tennis expert who called Naomi Osaka’s U.S. Open championship at 32-1. Over the past two years, Mair is up an astounding 213 units on his tennis futures picks. If you had placed $100 on each of those picks, you’d be up $21,300.

Now Mair has broken down Keys vs. Barty from every angle and released an extremely strong pick. He’s sharing it over at SportsLine.

Mair knows Keys handled Barty in the 2017 French Open (6-3, 6-2), but Barty returned the favor this February in the Fed Cup, winning 6-4, 6-1. In the most recent match, Mair noted to SportsLine, “Barty won 12 of the final 14 games and coaxed a whopping 31 errors from Keys’ racket.”

“However, Barty is very happy playing on an indoor surface but has yet to show she is a top-level player on clay,” he added.

While Keys has more clay-court experience and won her first clay-court title in April in Charleston, S.C., Barty’s game — especially her kick service and slice — is uniquely suited for the surface.

Neither player has faced an especially difficult draw. Keys easily handled the best opponent either player has faced, Katerina Siniakova, 6-2, 6-4.

During his exhaustive analysis, Mair isolated a critical X-factor that made him jump all over one side of this must-see quarterfinal. He’s sharing it, along with his exclusive best bet, over at SportsLine.

So who wins Madison Keys vs. Ashleigh Barty? And which critical X-factor makes one side of the match a must-back? Visit SportsLine now to see Gavin Mair’s best bet for Keys vs. Barty, all from the famed expert who called Naomi Osaka winning the U.S. Open at 32-1.