The major celebration of tennis in Spain is well underway now, and the relatively new clay-court Madrid Masters—can you even believe that for many years, Madrid was an indoor, hard-court event?—is a fitting tribute to all that the Iberian nation has come to mean to the sport, as well as an ideal showcase for the particular strengths of the fleet of players that one generation ago was dubbed “the Spanish Armada.”

Yet the intriguing question lurking beneath the surface these days is, “Is the Spanish era coming to a close?” David Ferrer and Rafael Nadal certainly are holding their own, respectively ranked Nos. 4 and 5. But Nicolas Almagro has slipped a bit (though still a highly respectable No. 12), and beyond that the fall-off is conspicuous. The next highest ranked player from Spain is—can you guess?—Marcel Granollers, followed by a resurgent Tommy Robredo.

Fernando Verdasco (career-high No. 7) and Feliciano Lopez (career-high No. 15), two pros in what undoubtedly will be known as the “Nadal generation,” are fading, quickly. Lopez is now No. 45, with Verdasco one notch below. So that’s seven players in the Top 50, but there’s a caveat. Three of those men are over 30 (Ferrer, Lopez, and Robredo), and Verdasco is just months shy of that benchmark age.

Nadal will turn 27 in just a few weeks, and he’s struggled with career-threatening injuries. Almagro is well on his way to 28 and Granollers, the baby in the bunch, is 27. Spain has 12 men in the Top 100, but not one of them is under 25, and players destined to contend for Grand Slam singles titles are usually identified by then.

So you have to wonder, is the sun setting on the dynasty Spain created over the course of two overlapping generations? (The earlier one featured Sergi Bruguera, Carlos Moya, Juan Carlos Ferrero, Albert Costa, Alberto Berasetegui and Alex Corretja—all Grand Slam champions or finalists.) Spain seems to be going the way of Pete Sampras’ USA and Bjorn Borg’s Sweden. That raises interesting questions about the nature of dynasty.

Many of you are familiar with the landmark work by Jared Diamond, Guns, Germs, and Steel. This interdisciplinary study of why societies rise and fall is breathtaking in scope and filled with marvelous insights. Alas, there’s no such work—Gut, Grass, and Graphite?—to help us understand why the tennis fortunes of nations mysteriously rise and fall as well.

Dynasties in tennis (and perhaps most sports) accomplish exactly the opposite of what they would appear to be doing at their height. Instead of creating a tradition that continues to build upon itself, champion begetting champion, new fans geometrically creating new fans, new infrastructure encouraging more new infrastructure, tennis dynasties often leave a scorched earth. Theories are advanced for why that happens, but none of them can be proved, and none of them can be applied successfully from one case to another.

It’s been said that the Swedish dynasty, created by Borg and advanced by Mats Wilander, Stefan Edberg, Anders Jarryd, and Joachim Nystrom (all were ranked in the top 10 at one time) failed because the cool Swedish climate just didn’t allow for enough gifted young players to develop adequate games in a rapidly evolving and newly professional environment.

Some say that U.S. tennis advocates were unable to recruit enough hungry, great young athletes to follow in the spectacular footsteps of Sampras, Andre Agassi, and Jim Courier—owing mostly to the lingering perception that tennis is a niche sport, and still too full of snobbish connotations. So how do you explain that the sport did, in fact, lure those three?

The Argentines, rabid sporting nationalists, are hampered by too little team spirit. In fairness, the charge was also leveled at the generation of Guillermo Vilas, Jose Luis Clerc, and Martin Jaite—a group that may not even qualify as a proper dynasty, but certainly made enough noise to help launch one.

The truth may be that there’s nothing wrong with Swedish tennis, nor with the collective game of any nation. The very idea that dynasty can be sustained over multiple generations is probably a fiction created by the staggering success of the three Anglo nations that really took to tennis and laid the foundations of the modern game: the United Kingdom, Australia, and the United States. Those nations dominated tennis through most of its history, and that’s no surprise (the era ended abruptly, after nearly a century, with the advent of “Open” tennis in 1968). For one thing, those nations were the first to create a broad tennis infrastructure of courts and clubs, which ultimately found peak expression in the major tournaments. Right off the bat, domestic players in those nations enjoyed greater playing opportunities and something like an inbred sense of superiority and security, while visitors were often just glad to be part of the festivities.

More important, three of the four Grand Slams well into Open tennis were grass-court events in which players familiar with the surface enjoyed a distinct advantage. Although the British gradually dropped out of the elite triumvirate, the Aussies and Americans milked their advantage to the hilt. And they had the populations, favorable climate, and available space to do it.

The U.S. and Australia enjoyed one other enormous advantage that has been wiped out by the tides of history. They were well-developed and relatively prosperous democracies, free societies where the pursuit of individual excellence—even under the kind of collective mentality promoted by legendary Australian coach Harry Hopman—was not just possible, but encouraged. But Open tennis, with its promise of riches and fame, was a game-changer—especially in Europe. And so was the collapse of the Soviet Empire.

Ilie Nastase joined Borg as the Open era’s European superstars. Nastase had the good fortune to be the son not of a lawyer but of a groundskeeper at Bucharest’s elite tennis club, Progresul. How could he not be exposed to and learn tennis? The surface throughout most of Europe is red clay, and tennis can thank France for helping to open up the game by resisting any temptation to abandon the surface. The fact that the French Open was the fourth major gave the clay game great credibility, and that offered a pipeline of sorts into the pro game for players raised on the surface.

Since Open tennis, the fortunes of every nation have waxed and waned. Dynasties or near-dynasties rise, and they fall. That appears to be the natural order of things, at least where you have anything like a level playing field, and adequate access to the game.

My own feeling is that there’s also something like “excellence fatigue,” and everyone is susceptible to it. Dynasties have a lifespan in the public imagination as well as the standings and results tables. Nations whose dynasties have crumbled needn’t look for complicated theories for why this is so—for every nation that rues the lack of a government-funded development program, there’s one with such a program that isn’t really achieving the desired result. For every nation that wonders where all the great players went, there’s another starting to churn them out.

Enjoy it while you still can, Spain. And don’t beat yourself up if and when it comes to an end.