!105055963 by Pete Bodo

Whatever happens in the Novak Djokovic-John Isner semifinal at the China Open will produce a bumper crop of those "irresistible force meets immovable object" moments. Tennis match-ups are tantalizing for any number of reasons having to do with strategy and/or technique, and sometimes for a variety of reasons beyond those.

For example, on any surface but clay, where the lefty high-kicking serve or forehand to the Roger Federer backhand is Rafael Nadal's version of the old Green Bay Packers' "power sweep" (you know it's coming, but you still can't stop it), a meeting between Roger and Rafa tends to play out kaleidoscopically. One of the two is doing something especially well or struggling a bit with some element in his game on the given day, which has a shaping influence on strategy and tactics. Sometimes one hot-zone in the battle cools off and another one replaces it. Suddenly, it's not about Rafa's wide slice serve to the backhand, but more about Roger's ability to penetrate and push Nadal back with his lashing, overspun backhand.

In some matches, the ability of Player A to find Player B's shaky one-handed forehand is key; in others, it's all about whether the retrieving ability of Player C will be able to handle the power and pace of Player D.

But the playbook for the Djokovic-Isner match-up will be remarkably and refreshingly thin. Nobody, regardless of details like service speed or first-serve conversion percentage, makes better use of his serve than Isner. And nobody makes better use of his return than Djokovic. It's an open and shut case. Will the Djokovic return—and return game—be unleashed, or bottled up by Isner's serving prowess? Remember, in beating Nikolay Davydenko, Isner hurled down 18 aces to Davydenko's one in the 6-3, 6-3 win. You don't need a pocket calculator to figure out the net-plus on that one. . .

But then, Djokovic is no Davydenko. I was somewhat surprised to see that Davydenko's name appears nowhere in the Ricoh ATP Match Facts statistics, at least not in the streamlined, week-to-week version that appears at the ATP website. I mean, Marcel Granollers makes an appearance (No. 10 in "Points Won Returning First Serve"), Jarkko Nieminen is No. 4 in first serve percentage (71 per cent), and Benjamin Becker wriggles in there on the leaderboard, right behind Roger Federer, at No. 7 in first serve points won. Admit it, wouldn't you have expected Davydenko to be in the Top 10 list in some serve or (more likely) return related category?

Djokovic, by contrast, is no lower than No. 4 in every one of the four Return of Serve Leaders categories, and at No. 1 on two of those lists. He's unrivaled in Break Points Converted (46 per cent) and shares the top spot with Juan Ignacio Chela in  Return Games Won (33 per cent). Incidentally, Andy Murray, Juan Carlos Ferrero, Nadal and David Ferrer are hot on the leaders heels in that latter division, all of them winning 30 percent or more of their return games. That strikes me as an awfully high percentage, given that serving is such a great advantage that the entire scoring system is based on the premise that if you break your opponent just once in a set, while you've been able to hold your own six times, you deserve the set.

One of the big-picture trends these days may be ongoing erosion of the logic behind that fundamental idea. A 33 percent conversion rate means you're winning two of every six service games your opponent is guaranteed in any set, which is actually double what you need to win the set. I'd be tempted to ask myself if my belief in the critical importance of the serve (and thus, the ability to break) isn't a bit outdated, but then there's always. . . Isner.

Ivo Karlovic, Andy Roddick, Robin Soderling, Tomas Berdych. . . all those guys have massive serves, yet none of them—or anyone else—seems to win simply by shooting out the lights in quite the same way as Isner. (Well, Karlovic does, but at this point he's down at No. 10 in the aces department, although he's still serving about the same percentage of aces per match as the leader, Isner.) Berdych and Soderling simply are excellent if not completely fluid or nimble players, blessed with great serves. They have more game with which to back up their serves, and in some ways I think they like for that to be known.

Great servers can be a defensive breed because some people feel it's just not fair to win points pre-emptively. In tennis, you're supposed to show your dexterity and skill on the fly, but the serve is the only stroke over which the ball-striker has total control, because he has the right to put the ball exactly where he wants, and hit it exactly how he wants, to start a point. And starting a point the way you want, or having the opportunity to do that, is the critical advantage bestowed on the server.

In the past few years Andy Roddick has worked furiously to show that he, too, is not just another pretty (big) serve. Roddick earned a lot of respect but he also may have lost some efficiency (and he certainly surrendered a little bit of that menace that is the birthright of all big servers) when he worked so hard, and with such encouraging results, to become a more multi-faceted player. It's doubtful we'll ever know for sure about that. But a comparison with Isner is inviting, and it helps put all this in perspective.

Isner is all about the serve and he doesn't care who knows it. Oh, he works on the other parts of his game, and wants and works to improve as much as the next guy. But he admits that he cleaves to the Big Man Canon as well as the cannon. He told me in the spring that he has no overpowering desire to win the Mr. Versatility prize. He has no interest in showing off what defensive or transitional skills he has. He wants to get points over quickly; the sooner the better. This is less an attitude than a strategy, and it pops up in some unexpected places (like some Federer vs. Nadal matches on red clay, which usually feature a paucity of what we call "typical" clay-court rallies).

Isner knows that having a better backhand and service return certainly would make him more dangerous, mostly because it would enable him to put even more pressure on his opponents than he already does by virtue of his serving skills. Most of the men he plays are scared stiff, and for good reason. They know you can't afford to get broken when your chances of breaking, never mind breaking back, are slim to none. And that can affect the quality of your own serving.

A number of players said of Pete Sampras, a paragon of the serve-driven game, that his ability and confidence in his serve was such that he would just cruise along, feeling no urgency to do much of anything but take care of his serve (usually, a relatively easy job). Inevitably as a returner he'd have a lead of 30-15, or even 30-all, and then he'd strike to get the critical break, or point in a tiebreaker. A pro can lose a 6-2, 6-4 match to a guy like David Ferrer and feel like he fought a valiant, exhausting, close war. But he can lose a 7-6, 7-5 match to a Sampras, or Isner, and know deep down that he was not only never in it, but he may not even need to take a shower and massage.

So I'm looking forward to seeing how Djokovic, the most lethal return-game player on tour today, will deal with the most unapologetic advocate of the pure, serve-based game, Isner. It promises to be, like so many of the other great stories, simple and majestic, but with one brilliantly conceived sub-plot: Djokovic is mighty proud of the way he's rehabilitated his own serve, which should help him neutralize that great advantage Isner has in so many matches: his opponents' fear of being broken.