W2W4 at Wimbledon: All-time great rivalry and a pair of ace-makers headline semifinals

LONDON -- The contrast between the two men's semifinals at Wimbledon couldn't be greater. First up, a pair of ace machines who will be on terra incognita, despite Kevin Anderson and John Isner each having a decade's worth of experience at Wimbledon.

The next pair up tell a very different story. Apart from having the most prolific -- and perhaps most compelling -- rivalry on the ATP Tour, Rafael Nadal and Novak Djokovic are titans of the baseline, adding further exploits to the record books.

Djokovic has taken sole possession of second place in Grand Slam semifinal appearances with 32 -- second only to Roger Federer (43). Nadal is now tied with Ivan Lendl in fifth place with 28.

Let's take a closer look at the matchups, starting with the headliner:

No. 2 Rafael Nadal vs. No. 12 Novak Djokovic (Djokovic leads series 26-25)

The worrisome statistic for Djokovic, particularly if he's at all superstitious, is that Nadal has never lost a semifinal at Wimbledon, and that includes a 2007 win over Djokovic, who retired during that match with an infected blister on a toe. Nadal is coming off an enormous, emotional quarterfinal win against Juan Martin del Potro, a performance that big four cohort Andy Murray called "the best live match I've seen in my life." Simona Halep seconded the motion in a tweet.

Nadal came into this Wimbledon feeling he was owed one. Players who win here usually lead somewhat charmed lives, but not Nadal. His hard-luck tales of recent years were underscored last year. Just when he thought his Wimbledon luck might had turned, he found himself playing a huge hitter in Gilles Muller as his fourth-round opponent. Nadal fell in a 15-13 in-the-fifth loser.

It can happen to anyone, only it doesn't. Not with such frequency. But it kept happening to Nadal even though as a five-time finalist and two-time champion in London he should have radiated beautiful, Federer-esque karma. Now Nadal may be on the verge of putting it all behind him.

Djokovic has a beef, too. In fact, he has had plenty of beefs over the fortnight, and they seem to have made him a sharper, more dangerous and confident competitor. There was that shockingly bad call in his match with Kyle Edmund, and the fans who heckled him for bouncing the ball too many times. Then there was the late start in the gusting winds on Court No. 1 on Manic Monday. "I've played this year so far only once in first four matches on Centre Court," Djokovic groused after winning that one. "It helps [to play there] as you progress through the tournament."

In the quarterfinals against Kei Nishikori, Djokovic incurred a code violation for racket abuse. The chair umpire said Djokovic damaged the grass when he tossed his racket, but the player said it barely grazed the turf. The distinct flavor of the playground permeated Djokovic's claim that Nishikori also tossed his racket in the fourth set, but that went unpunished.

"[The official] claims he didn't see what Nishikori has done, but apparently he always sees what I do," Djokovic sniffed. "Something that I don't think is fair."

How about the news that the US Open will be using an on-court shot clock for main-draw matches, a decision that sat wrong with Djokovic because neither he nor the other players had been consulted.

On the whole, it's been a tough, challenging tournament for the beleaguered Serbian star, but perhaps that's a good sign after the way he moped around earlier this year, insecure and searching his soul. His game is undoubtedly falling into place; every man he has cut down and those watching have felt he's at or very close to his pre-slump level.

"I saw matches of him," Nadal said on Wednesday. "He's playing great."

These men know each other's games inside out, but if one of them has a surprise in store, it's probably Nadal. He made great use of the drop shot in his win over del Potro, and he made a great case for continuing the tactic.

"Sometimes is a good way to change the rhythm of the point against a player that hits so strong," Nadal said. "Here on grass, if you make a good drop shot, is so difficult. Is very difficult to stop your legs when you arrive there. The second bounce goes down very, very quick."

Djokovic doesn't hit as big a ball as del Potro, but as a great defender, he's likely to be caught farther behind the baseline on more occasions. Stopping after a full-on sprint is equally difficult for all players. Don't be surprised to see Nadal use the drop shot with some frequency.

No. 8 Kevin Anderson vs. No. 10 John Isner (Isner leads 8-3)

This is the Wimbledon of a lifetime for Isner. The only hitch in the fairy tale is that it's the same thing for Anderson -- and only one of them will know the thrill of being a Wimbledon finalist.

The head-to-head record suggests that will be Isner, who has dominated the rivalry, winning their past four meetings and five of their past six. Anderson's greatest edge may be that he has been in a Grand Slam final, having lost the US Open championship to Nadal last September.

Isner, at 33, is the oldest among this quartet of over-30 semifinalists. He's having a career year. By his own admission, he had a rough start to 2018, winning just two matches going into the Miami Open Masters 1000. But in the days before that event, his coach, David Macpherson, convinced Isner in a series of conversations to shed his fear of losing and just swing away, play freely, and enjoy himself. Isner has been doing that -- and winning -- ever since.

Anderson has had no such epiphany. His is a saga of relentless hard work and diligence, gradually reaping greater and greater rewards. The best thus far was a stunning quarterfinal upset Wednesday against Federer. The residual question is how much emotional capital did Anderson leave out there after that five-set win, in which he lost the first two sets and stared down a third-set match point.

Isner and Anderson are in first and third place, respectively, for most aces served at the tournament this year. (Isner has blasted 160, Anderson 124.) Each of these men has played one five-setter on the way to the semis. Anderson has played five tiebreakers (winning three) to Isner's seven (he has won four).

Anderson's groundstrokes were impressive in his win over Federer, but Isner's serve hasn't been broken in this tournament. Anderson has his work cut out, but after having to meet Federer a few days ago, he's accustomed to that feeling.