Despite the utter domination imposed on the ATP by the Big Four and way Serena Williams has been riding roughshod over the WTA, recent times have been rich in producing interesting and often unexpected trends. These include the embrace of polyester strings that, because of their lack of elasticity, were once used only by cash-poor hackers; also, the explosion of stylistic variety in the women’s game, and the demolition of what once seemed a self-evident axiom of the Open era: That tennis would increasingly become a game dominated by young players.

The latest development that caught us by surprise is the boom in employment opportunities for wildly rich and globally celebrated champions just one or two generations removed from the present one. The list of men’s Grand Slam champions who have dipped their calloused toes into the coaching waters recently is vast: Goran Ivanisevic (with Marin Cilic), Sergi Bruguera (with Richard Gasquet), Michael Chang (with Kei Nishikori), Jimmy Connors (ever-so-briefly with Maria Sharapova), Ivan Lendl (with Andy Murray), Boris Becker (with Novak Djokovic) and Stefan Edberg (with Roger Federer).

Pete Sampras is said to be interested in helping, or at least advising, young Jack Sock. Bjorn Borg may be holding out, but would you be shocked if you had heard that hotheaded Jerzy Janowicz befriended John McEnroe? I can’t substantiate that, but given what’s going on, quién sabe?

And if I were Jim Courier, I’d just sit back and entertain offers. All he needs is a player with a level of potential commensurate with what Courier has to offer, but that seriously diminishes the candidate pool.

So what do we make of all these alliances of titans? A part of me thinks that we’ve now entered the era when the top players earn so much that they can afford “trophy” coaches, although I wouldn’t for a moment denigrate what Lendl and Murray have achieved together. In fact, I think it was Lendl who made the world safe for celebrity coaches.

Ironically, the champ who launched this entire trend probably was Lendl’s one-time mentor, Tony Roche. While the Australian legend was unable to push Lendl over the finish line in his quest to win Wimbledon, the partnership was so successful that Roche later found work with both Lleyton Hewitt and, most famously, Federer.

Still, Roche was a player from a bygone era. Great as he was, he played before the time when great players became household names with overflowing bank accounts. The new barbarians of Open tennis—Connors, McEnroe, Borg, Nastase—were a different breed. All else aside, they were stars of such magnitude that it was difficult to imagine any of them suppressing their egos to the degree required by the coaching profession. And they had no need to continue earning in order to meet the mortgage payments.

Connors was the first of the marquee, Open-era names to accept the risks and rewards of signing on as an “official” coach when he agreed to guide Andy Roddick for a hefty sum in 2006. (To see how far we’ve come, Djokovic’s camp seemed to take pains to formally name Becker “head coach.”) But Connors was unable to get Roddick over the hump to win another major, and the relationship ended after 19 months. At the time they quit, it seemed that the partnership could not be sustained once the basic novelty of it wore off—or once Roddick grew tired of signing those big checks.

It was quiet for some time after that, and then in late 2011 Lendl signed on to coach Murray. Given his blunt, frequently abrasive manner, Lendl’s relationship with the phlegmatic Murray had the potential for disaster. That they were able to avoid a clash of egos—or sensitivities (and Lendl has plenty, hard as he works to hide them)—was a signal victory. So was their ability to make real, daily progress. Some of this surely was due to Murray’s talent. But clearly Lendl brought to the table something no garden variety coach could provide, and he was devoid of any desire to rub his protégé’s nose in it. That something was the rarest of all commodities in tennis—a degree of big-match experience equal or superior to that of all but the absolute best of players.

There’s always been a kind of integrity about the Lendl-Murray relationship, partly because Lendl is as indifferent to the fruits of celebrity as a coach as he was as a player. Any former champ who had hang-ups about playing second fiddle to an active player, or feared his reputation as a leading man might be tarnished by taking a turn as supporting cast could look at Lendl and think: Hey, this worked out pretty well for those two—maybe coaching isn’t such a bad gig after all. . .

It’s easy to see why Grand Slam champs would flock to the coaching ranks now that the ice has been broken. Almost all players miss the electricity and atmosphere of big-time tennis; who wouldn’t? Also, in today’s game the coach has become a mouthpiece for his player—and a celebrity in his own right—chased by media and sponsors alike. This will appeal to some legends more than others, but the one thing all of them will share as coaches is the sense that they’re relevant and right in the thick of things, rather than at the fringes of the action. It’s a lot different from attending the tournament as a VIP guest, making small talk with sponsors, and then returning alone to your hotel room at the end of each day.

And of course, Becker will be glad to see Edberg again, and both of them will take undeclared pride in beating each other through their proxies, or taking that Lendl down a peg or two.

We also know one thing for sure: It’s unlikely that Becker, Edberg, Lendl, and Chang will enjoy equal measures of success, even in the relative terms dictated by the track record and résumé to date of each man’s protégé. So let’s take a quick look at how these pairings might pan out in 2014:

Lendl and Murray: This pair is beyond having to prove anything to anyone, and having been the first of the celebrity pairings, they’ll be motivated to demonstrate that they’re still the best. They have a great head start in that regard, and face a question the other partnerships at this point can only wish to face one day: How do you get better and achieve more? Make no mistake: Lendl and Murray are the gold standard.

Chang and Nishikori: Chang won only one major in his career, and would be wildly successful if he could help Nishikori get one of his own. At the peak of his powers at 24, the best player out of Japan has stalled in the second ten of the rankings. Chang’s challenge will be to get Nishikori to play with a little more consistency and patience. A model of disciplined determination, Chang will try to get Nishikori to believe in himself and keep his level of aggression high but well modulated.

Bruguera and Gasquet: This is a tough one to figure. Bruguera could almost be called the anti-Gasquet: Where the Frenchman is flamboyant and bold, two-time French Open champion Bruguera was methodical and content to play from an ultra-defensive position. Bruguera might be able to get Gasquet to take a little off and play a little more consistently, but both men are most comfortable playing from meters behind the baseline. That’s an enormous handicap for Gasquet, and you have to wonder what Bruguera can do to alleviate it.

Becker and Djokovic: Becker was well-known for his willingness to risk all and play with courage and aggression—even when he was in desperate straits. Djokovic played in three Grand Slam finals and one semifinal in 2013, but walked away with just one major title. He has said that he’s counting on Becker to advise and guide him through that handful of moments that spell the difference between winning majors and accepting the runner-up trophy.

Just as Lendl was able to loosen up Murray, Becker may be the man to get Djokovic to meet his destiny at those critical moments with a smile and loose arm rather than a scowl and tense grip.

Edberg and Federer: The six-time Grand Slam champ from Sweden and the all-time Grand Slam singles title record holder from Switzerland are a kind of “dream team” for anyone enamored of elegance and class. Federer has an enormous respect for tennis history and tradition, so it’s a given that he’ll enjoy hobnobbing and swapping tales and theories with Edberg. The big question is, did Federer recruit Edberg in the hopes that, as one of the last great practitioners of the all-in serve-and-volley game, the Swede will help him develop a more lethal attacking game?

It would be an astonishing stroke for the 32-year-old icon who’s drifted down to No. 6 in the rankings, but we learned some time ago that you can’t ever underestimate Federer’s resilience.