Serena Williams will continue her quest for Grand Slam history on Monday as the top half contests the Round of 16. We're previewing the matchups at WTATennis.com, courtesy of contributor Chris Oddo.
Round of 16
 Serena Williams (USA #1) vs. Yaroslava Shvedova (KAZ #52)
Head-to-head: Williams leads, 4-0
Key Stat: Williams is bidding to pass Roger Federer for the all-time lead in Grand Slam match wins on Saturday.
Serena Williams waltzed through the first week in New York, dropping a mere 15 games and proving to the field that her serve is on point. The shoulder is fine, the footwork is fine and the game is dialing in. Now, the 22-time major champion moves on to the business section of the draw. It starts with a fifth career meeting with hard-hitting Kazakh Yaroslava Shvedova. Williams has taken all four of the pair's previous meetings, but one shouldn't discount the talents of Shvedova. The World No.52 has won all six sets she's played in New York to reach the second week at a major for the sixth time. She has the firepower to challenge Williams, but does she have the nerve? Approaching 35, and closing in on the all-time Open Era Grand Slam title record, Williams seems more motivated than ever to win. "I don't know," she said on Saturday after storming past Johanna Larsson of Sweden. "I just am not ready to throw in the towel yet or just to have enough yet. I'm still having fun out there. I'm still able to compete with the best. I think that's what matters most for me."
Pick: Williams in two
 Agnieszka Radwanska (POL #4) vs. Ana Konjuh (CRO #92)
Head-to-head: Radwanska leads, 1-0
Key Stat: Radwanska is one of four players to have reached the round of 16 at all four majors this year (along with Serena Williams, Keys and Suárez Navarro).
The last time Agnieszka Radwanska and Ana Konjuh locked horns, intense drama ensued. The pair battled into extra time in the second round at Wimbledon this year, with Radwanska saving three match points in the final set before winning, 6-2, 4-6, 9-7. Making the experience all the more painful for Konjuh was the fact that she turned her ankle after stepping on a ball at 7-7 in the decider and was severely hobbled at the finish. Less than two months later promising 18-year-old Konjuh has put the past behind her and raced into the round of 16 at a major for the first time in her career. On Monday the youngest player remaining in the draw gets to try to erase the memory of a Wimbledon gone awry. Can she possibly produce the type of tennis that earned her the three match points against Radwanska at the All England Club? Or will the No.4 seed have the perfect gameplan to ensure that Konjuh is kept at bay all day?
Pick: Radwanska in three
Simona Halep really had to work to get past No.31-seeded Timea Babos on Day 6. Down a break in the third set and playing at a level or two below her best, Halep had to double-down on intensity and grind her way to a win. She did that, despite Babos' inspired form, and lives to see another day in New York. "I don't know how I came back," a relieved Halep said on court after her 20th hardcourt win of 2016. Will Halep's narrow escape fuel her belief when she faces the proven veteran Carla Suárez Navarro for a spot in the quarterfinals? "Even if today I didn't play my best, I played good tennis, good level," said a confident Halep to reporters. "I was moving very well. I am happy to be back in the fourth round two years in a row, so it's a good thing." Halep and Suárez Navarro have gone the distance in each of their last three meetings, and they've split a total of ten matches since they first met in 2010. Who will break the tie on Monday?
Pick: Halep in three
 Karolina Pliskova (CZE #11) vs.  Venus Williams (USA #6)
Head-to-head: Williams leads, 1-0
Key Stat: The last time No. 6-seeded Williams was seeded this high in New York was 2010, when she was the No. 3 seed.
Finally, Karolina Pliskova has reached the second week of a major. The hard-serving Czech had been pining for the milestone ever since she emerged as a formidable force among the WTA's elite at the start of 2015, but in the last two years she's had nothing but hard luck at the majors. Not anymore. The 24-year-old surged past Anastasia Pavlyuchenkova on Saturday and will now set her sights on legendary Venus Williams in what promises to be scintillating round of 16 encounter. Two-time US Open champion Williams continued her fine showing in New York by blasting past Germany's Laura Siegemund, 6-1, 6-2, on Saturday. The American defeated Pliskova in the Zhuhai final last year but Pliskova will likely carry more confidence into this tilt. She has won eight matches in a row, four of which came against members of the WTA's Top 20.
Pick: Pliskova in three
By the Numbers:
307 - Matches won by Serena Williams at majors. She'll bid to pass Roger Federer's all-time record of 307 on Day 8.
428 - Pliskova leads the Tour with 428 aces in 52 matches this year.
9 - Of the nine teenagers that started in this year's US Open main draw, Konjuh is the only one remaining.