NEW YORK – The men have been true to form for the most part during this year's U.S. Open. That that means, with four round-of-16 matches on tap for Monday, that the only two current Grand Slam champions in the draw are relegated to Louis Armstrong Stadium.
Wimbledon champion Novak Djokovic and Australian Open champion Stan Wawrinka – a very low-key presence so far in this tournament – are there.
Why? Well, CBS has the choice of the one men's match it can show during its daytime broadcast window. None of the parties involved wear the red, white and blue, and none of them are Roger Federer. It seems they wanted what could be the most compelling matchup – not the one involving the highest seeds. They've chosen Jo-Wilfried Tsonga (No. 9 seed) vs. Andy Murray, the 2012 champion and No. 8 seed in the tournament.
As for the women, it has been an upset-heavy event, with the only top-10 seeds remaining both in the top half both playing today. No. 1 seed Serena Williams takes on Kaia Kanepi, a former French Open junior champion who, every once in awhile, makes a run at a Grand Slam. This is that run.
The other top-10 seed, No. 7 Eugenie Bouchard, will play during that daytime window, but in the afternoon on Louis Armstrong Stadium.
The most noteworthy scheduling decision was to put 15-year-old Cici Bellis, who made headlines during the first round of the women's event when she upset No. 12 seed Dominika Cibulkova of Slovakia, on the Grandstand court for her ... first-round junior singles match.
That's ludicrous, of course. If they were going to choose an American story to spotlight there, a better choice would have been the mixed doubles team of Tayor Townsend and Donald Young, who have a winnable match in the quarterfinals. The Chicago natives, who have a long history of friendship between their two families and are both African-American, are a much better story. But they're relegated to Court 17, as CBS clearly wants to play catch-up on last week's story of the young prospect who, the narrative goes, had a "great run" at the U.S. Open.
She didn't; a "run" would imply more than one match; Bellis lost in the second round. It was an impressive win for a 15-year-old. But it was one win. But hey, why spoil a good narrative?
MATCHES TO WATCH - WOMEN
Who is Kaia Kanepi? The 29-year-old is from Estonia, which isn't exactly a tennis hotbed of a nation. Two years ago at this time, she was ranked No. 15 in the world but currently is right at No. 50 – a number that will jump with her fourth-round effort in New York. She and Williams have met three times, with Williams winning all three in two competitive sets. But they haven't played each other in nearly five years.
It's a decent test; Kanepi defeated both Carla Suárez Navarro and Samantha Stosur along the way (that one was in a third-set tiebreaker, after Stosur served for the match). But Williams, unless her nerve fails her, probably won't have too much trouble.
Krunic looks like she should be in the juniors, with her diminutive stature and the braces on her teeth. But she has played like a heavyweight during this U.S. Open, defusing the power of two of the hardest hitters out there in American Madison Keys and Wimbledon champion Petra Kvitova, the No. 3 seed.
She has six match wins in this tournament, including three in the qualifying. In Azarenka, she faces a player who hits hard, but who has more options than the previously-mentioned two. A year ago, Azarenka was fighting Serena Williams tooth-and-nail in the final; this year, after a foot injury cost her a lot of time, she's the No. 16 seed and is nursing a knee twisted during the tournament in Montreal a few weeks ago.
MATCHES TO WATCH - MEN
 Andy Murray (GBR) vs.  Jo-Wilfried Tsonga (FRA)
When the draw came out, this possibility was certainly an enticing one. And both players made it to their appointed date in the fourth round.
Tsonga is powerful, flashy, charismatic, everything you want in your favorite tennis player. But he's never had that big-time breakthrough, the one that makes you think he could challenge the very top guys consistently even if his talent dictates he has the potential. At 29, time is running a little short. But the Frenchman was the hottest player on form coming into New York, along with Federer; He defeated FOUR top-10 players on his way to the title at the Masters 1000 tournament in Toronto a few weeks ago: Novak Djokovic, Grigor Dimitrov, Murray (7-6(5), 4-6, 6-4) and Federer in the final.
Murray is rounding into form; after back surgery nearly a year ago, it has taken him time to find all his bearings again. He has had a few momentary lapses on the road to the fourth round, but nothing drastic.
These two are considered among the top contenders for those very top spots in the rankings, when and if the current group ever gets old and slows down, which doesn't appear imminent.
They are very different players, both in size and game style. And that can make for a compelling matchup. Raonic serves as well as anyone in the game; Nishikori returns as well as anyone in the game.
They've met three times: the first was in 2012 in the final of the ATP Tour event in Tokyo, in Nishikori's home country. The next came in Madrid on clay this year when Raonic was playing very well – but Nishikori was on a cloud. Had he not had back issues, he was well on his way to defeating Rafael Nadal to win the event.
They were supposed to meet at the French Open in the same fourth round, but Nishikori didn't make the date. They did meet at Wimbledon, and Raonic won in four sets. It's awfully hard to pick a favorite in this one.