1. Alexander Zverev  vs. Ernests Gulbis
The 21-year-old Zverev and the 29-year-old Gulbis have never played, but they know each other. Gulbis was a houseguest of the Zverevs during a training trip when he was younger. They also share a common strength: Their two-handers. We often talk up matches that are “showcases for the nearly-extinct one-handed backhand”; this match will showcase the two-hander, and remind us how good it can look, and how useful it can be. As far as who is going to win, that’s a tougher call than it might appear at first. Yes, Zverev is ranked far higher; while he was winning Madrid and reaching the Rome final, Gulbis was playing Challengers in Bordeaux, Prostejov, and Caltanissetta. But Gulbis beat Juan Martin Del Potro here last year, and he qualified for this main draw, so he should be as match-tough as he’s going to get. And Zverev has a habit of letting lower-ranked opponents hang around in best-of-five-set matches. Winner: Gulbis
WATCH—Daily Serve from Day 5 at Wimbledon:
2. Angelique Kerber  vs. Naomi Osaka 
Osaka hasn’t been on tour for long, but she’s already faced Kerber three times. She won the first of those matches, in the opening round at the US Open last year. But Kerber came back later in the fall to win their last two meetings in routine fashion. Osaka has improved immensely since then, but how will she fare against a former Wimbledon finalist on grass—and not just on any old grass, but Centre Court grass? If her last match, a three-set comeback win over Claire Liu, is any indication, Kerber can be pushed around by a strong young opponent. But it also showed that, with so many opportunities ahead in the depleted women’s draw, Angie is ready to fight with everything she has to push back. Winner: Kerber
3. Kei Nishikori  vs. Nick Kyrgios 
Kyrgios called Nishikori a “nightmare” earlier this week. If you’ve seen any of their three meetings, all of which have been won by Nishikori, you’ll understand what Kyrgios is talking about. Kei returns Kyrgios’s serve, runs down his ground strokes, and makes him hit far more balls than he’s interested in hitting, or that he can keep in the court. When it comes to rallies, Nishikori’s ultra-smooth, ultra-solid two-handed backhand has proven much more reliable than Kyrgios’s more-makeshift version of the same shot. Yet the Aussie also made a good point in his own favor, when he said that his game is better-suited to grass than Nishikori’s. Kei has never been past the fourth round here. Whoever prevails, this one should be intriguing. Winner: Kyrgios
Strokes of Genius is a world-class documentary capturing the historic 13-year rivalry between tennis icons Roger Federer and Rafael Nadal. It is timed for release as the anticipation crests with Roger as returning champion, 10 years after their famed 2008 Wimbledon championship – an epic match so close and so reflective of their competitive balance that, in the end, the true winner was the sport itself.