Let's consider the current state of the U.S. Open men's draw.
The top half of the draw is relatively intact. Both No. 1 seed Rafael Nadal and in particular No. 3 Roger Federer have looked vulnerable, but everyone's preferred semifinal is still happening as of now. In their way are the likes of No. 6 Dominic Thiem, No. 9 David Goffin, No. 18 Gael Monfils and No. 24 Juan Martin del Potro—a fairly robust, if slightly thin, list of challengers. A couple big names are out earlier than expected, like Nick Kyrgios and Grigor Dimitrov, but everything on this side is still pretty normal.
Then there's the bottom half of the draw. It was already relatively open even before No. 1 Andy Murray withdrew before the tournament. The following players have been eliminated since the tournament began, all of whom could have plausibly made a run to the semifinal: No. 4 Alexander Zverev, No. 8 Jo-Wilfried Tsonga, No. 13 Jack Sock and most recently No. 5 Marin Cilic, who fell to Diego Schwartzman in four sets on Friday.
As of 3 p.m. ET on Friday, here are seeded players remaining in the bottom half of the draw: No. 10 John Isner, No. 16 Lucas Pouille, No. 17 Sam Querrey, No. 23 Mischa Zverev, No. 28 Kevin Anderson and No. 29 Schwartzman.
The dearth of top players in the bottom half is, to put it mildly, unusual. We're accustomed to seeing the same players compete again and again in Grand Slam finals, but with so many players skipping the year's final major due to injury (Djokovic, Wawrinka, Murray, Raonic, Nishikori) and other contenders bounced in the first week (namely Cilic and Zverev), we're actually guaranteed to see a first-time Slam finalist. Of the remaining players on the bottom half of the draw, only Sam Querrey has made a major semifinal.
In other words, you need to start mentally preparing yourself to hear the phrase "U.S. Open semifinalist Pablo Carreno-Busta" or "Grand Slam finalist Sam Querrey." It's hard to even identify a favorite at this point. Whoever emerges from Cilic's quarter and Zverev's quarter will be players who typically don't reach the second week, much less the semifinals. John Isner is the best remaining seed, but Cilic's loss allows basically any remaining player in the bottom half to envision a realistic path to the semifinal. For players like Isner and Querrey, it's the opportunity of a lifetime—a plausible road to the final of the U.S. Open, with no obvious insurmountable challenge in their way. If Querrey and Isner meet in the fourth round, the winner will likely be favored to reach at least the semifinals.
Prognostication is a dangerous game, especially considering the results of the last few days. But I'd split the contenders to reach the semis into two main groups. On one side are the middling veteran players, hardly regular contenders at majors, who have a legitimate shot to reach the final. In this category I'd place Querrey (who came close at Wimbledon this year), Isner and Anderson. Then there are the young players who might one day be major contenders, but who are breaking through earlier than expected. Lucas Pouille, Denis Shapovalov, who upset Tsonga, and Borna Coric, who knocked out Zverev, are the three most notable players in this category.
The year 2017 has been defined by chaos, and we're learning that even men's tennis—a sport dominated by three or four people over the last 15 years—isn't immune. Bring it on.