Zverev v. Shapovalov; Nadal, Kyrgios in dubs highlight Laver Cup Day 1

Quick thoughts on each of Day 1's four matches at the inaugural Laver Cup:

Given Cilic's struggles since the Wimbledon final, where a blister hindered him physically and sapped him mentally, you'd think this would be a good opportunity for Team World to steal an early point. But Tiafoe—filling in for the injured Juan Martin del Potro—is by far the least accomplished player of the dozen in Prague, and shouldn't be counted on. The American more than held his own against Roger Federer at the US Open, but that was in front of a crowd that, if not all behind him, still showed him heavy support. To Cilic's credit, he won two rounds in Flushing Meadows, along with two Davis Cup playoff rubbers last week. If he's back where he needs to be physically, Tiafoe shouldn't pose a threat.

In the latest Tough Call, I picked Team World to win the Laver Cup, and the event's format factored into that decision. If the first two sets are split, matches will be decided by 10-point tiebreakers—one of Isner's specialties. Isner doesn't need to win three sets, a demand which has undone him at both Grand Slams and in Davis Cup, to get the job done for Team World. But it's not as if Isner can't win overseas, in international team competition, either: in 2012, he shocked Federer in Switzerland. I think Thiem, whose last match was an inexplicable collapse to del Potro in New York, goes down.

The night session begins with the day's most tantalizing match—with apologies to Andrey Rublev, these are game's two best young talents. Their disparate rankings should be taken with a grain of salt, as it's the world No. 51 who will enter this match with more momentum. Ever since the beginning of the Rogers Cup—an tournament Zverev won, and in the process defeated Shapovalov—the Canadian has surged, and for a time he was thought of as a possible US Open champion. Zverev, meanwhile, has lost some of the edge he's held through most of this breakthrough season. After an early exit at the Open, this would be a big stage on which to recoup some of what has been lost.

The most intriguing match of the day—and possibly of each day—is the doubles. In one corner you have Kyrgios and Sock, two buddies that play similarly high-octane games. In the other you have Nadal and Berdych, whose games couldn't be more different, and who long ago, in Madrid, had something of a squabble with each other:

That's in the past, of course, and the Czech fans will be firmly behind both Europeans. It casts Kyrgios and Sock in the roles of villain, something I could see each them relishing (and something, quite frankly, Kyrgios has experience in). This one's tough to call, but it's hard to go against the crowd favorite, Berdych, and one of the more underrated doubles players of our generation, Nadal—who just happens to be a 16-time Grand Slam singles champion.

How Laver Cup works: