Fritz, an 18-year-old Californian, says that playing Wawrinka will be “complicated.” That sounds like a euphemism for difficult, challenging, maybe even scary. Fritz burst into the Top 100 this winter with a smooth backhand and a smoother serve; he did things, like win a title in his third tournament, that Sampras and Agassi never did. Since coming to Europe this spring, though, he has come back to earth; Fritz has lost seven of his last nine matches, though he did push Roger Federer deep into a third set on grass. Wawrinka, though, may actually be a higher Swiss mountain for the skinny rookie to climb; it's doubtful whether he has ever faced raw, heavy power like Stan's before. Fritz has a usefully versatile serve, and Stan can struggle on his backhand return, but the American will have to get the most he can out of that dynamic. If Wawrinka is off, Fritz may be able to stay with him, but Stan, who has reached the quarters at Wimbledon the last two years, isn’t off at the majors too often these days.

Winner: Wawrinka

The 21-year-old Aussie and the 37-year-old Czech have met once; three years ago at the French Open, Kyrgios won in three tiebreakers. Since then, Kyrgios has only gotten better, while Stepanek has only gotten older. Now, they’re ranked 18th and 121st, respectively. Kyrgios will be the favorite, and especially so at Wimbledon, where he is 7-2. But while it would be surprising if Stepanek won, it would be even more surprising if, at some point, he didn’t make the match entertaining, while also digging his way some distance under Kyrgios’ skin with his nerdy antics and smoke-and-mirrors style. Either way, this battle of youthful power vs. aging guile on Court 2 should be worth a watch.

Winner: Kyrgios

Which stat is more important? The fact that Mayer is ranked 80th, precisely 72 spots behind Thiem? Or the fact that Mayer has won seven of the eight matches he’s played on grass leading up to Wimbledon, one of which was a 6-3, 6-4 victory over Thiem himself? Thiem has youth on his side; he’s 22 to Mayer’s 32. He  also has the advantage in power, speed and, with four titles on three surfaces this season, confidence. But Mayer has a funky game that could throw anyone out of whack, especially a relative grass-court novice like Thiem, who has played just three matches at Wimbledon and lost two of them. As I wrote about Kyrgios and Stepanek above, this battle of youthful power vs. aging guile on Court 3 should be worth a watch.

Winner: Thiem