The era of a Big Four in men's tennis emerged in year 2008, when Andy Murray climbed upward to join Roger Federer, Rafa Nadal, and Novak Djokovic atop the world pro rankings. The identical foursome in varying order led the men's rankings for the next four years, thus achieving a domination in the sport for five consecutive years. Meanwhile in an overlapping period, 2006-2013, the same four superstars captured every Slam but one, along with both Olympics during the period and all but one Master's Cup. Recognition is now widespread, that this has indeed been an era of the Big Four in men's singles, one surpassing even the run of the French Musketeers and Bill Tilden in the late 1920's.
 
The modern Big Four splintered, perhaps temporarily, in 2013, when Federer, slowed by injuries at age 32, finished the year outside the group. Meanwhile the other three finished within the top four, even Murray who was long sidelined for back trouble and then surgery. But the foursome's dominance again declined in early 2014 when outsider Stan Wawrinka became the unexpected winner at Australian Open and then again at Monte Carlo.
 
But the individual careers of the Four remain unfinished, assuredly those of Nadal, Djokovic, and Murray, who are all still at prime age. Here, we examine how the group members currently stack up on the scoreboard of individual career greatness. We seek perspectives on their chances for climbing higher.
 
COUNTING SLAM TRIUMPHS
 
The usual way of comparing career achievements is by counting triumphs in Slams. It is the most convenient method and is also highly revealing, although it is deceiving for several decades prior to 1968 when many of the world's best players, having turned professional, were not permitted to compete in Slams.
 
Here are the present leaders in the all-time tally of Slam triumphs:
 
Roger Federer, 17
Pete Sampras, 14
Rafael Nadal, 13
Roy Emerson, 12
Bjorn Borg, 11
Rod Laver, 11
Bill Tilden, 10
 
Atop the list is the great Federer, now 32, whose current performances against his strongest opponents are often brilliant, at times equaling his finest ever. But for Roger the triumphs come less frequently, and it is unmistakable that several younger players are now capable of defeating him, especially in long matches. Roger has captured only one Slam since Australia 2010.
 
Roger's lead in career Slam triumphs, above, is secure over second-place Pete Sampras, whose final Slam win came at age 31 at U.S. Open 2002. But Roger's margin over Rafael Nadal, still at prime age and in third place, above, is not yet conclusive. Knee troubles have hampered Rafa in recent years, but he has nevertheless gradually closed on Roger, Rafa having captured Garros and U.S. Open in 2013.
 
Nadal and Federer have been locked in their rivalry ever since Rafa entered the world's top hundred at age 17 in 2003. In head-to-head results Rafa has the strong edge on clay, the two are about even on nonclay, and Rafa is thus well ahead overall. Given Rafa's eight triumphs in the last nine years at Garros, Rafa should be the favorite to capture Garros 2014 next month, where his powerful spins will have full effect on the red-clay bounce. A net gain of at least one Slam for Rafa in 2014 thus seems possible, indeed probable.
 
But the more sizzling rivalry for dominance atop the men's game is now between Nadal, now nearly 28, and the stylish Serbian Novak Djokovic, who is the younger by one year. Both Rafa and Novak have won five Slams since the start of 2011, three of Rafa's coming at Garros, three of Novak's at Australian Open. If both are equally healthy, Rafa will be favored at Garros 2014, Novak probably at Wimbledon and U.S. Open.
 
Djokovic has developed a strong baseline-oriented game, where his patience and determination in winning long, extended points contradicts a sometimes jocular public manner. He is a magnificent mover, a potent shot-maker, superior to Nadal on nonclay but unlikely to defeat Nadal on clay unless Rafa is hampered physically. Bothered by a right wrist that was heavily wrapped, Djokovic lost to Federer at Monte Carlo in April in the year's first meeting among the Big Four on clay. Novak has remained sidelined since then.
 
Djokovic has won six Slams in his career to date, standing well behind the leaders in the career Slam count. But a few more conquests would lift him ahead of several retired luminaries, among them Agassi, Perry, Lendl, Connors, Rosewall, Budge, and McEnroe. Reaching or passing Bill Tilden's seventh-place total of ten career Slams is a plausible target for Novak.
 
Andy Murray, like Djokovic, will soon turn 27. So far Andy has won two Slams -- Wimbledon and U.S. Open, each once. His superb court mobility matches that of the other members of the Four, and he may surpass them in his easy power and variety in shot-making. But back surgery in 2013 and recent injury problems diminish his immediate prospects, so that his chances of breaking into the top group seem for now unlikely.
 
GRAND SLAMS
 
Winning all four of the Slams is a Grand Slam, a term borrowed from the game of bridge during its early popularity in the 1930's. Men's tennis has long awaited its next Classic Grand Slam, last seen 45 years ago.
 
Classic Grand Slams
 
The Classic Grand Slam requires winning all four Slams in the same calendar year. It has been achieved three times by male players -- by Don Budge in 1938 and by Rod Laver in 1962 and 1969. Budge's in 1938 was diminished by the absences of von Cramm and pros Perry and Vines, Laver's in 1962 by the absences of pros Rosewall, Hoad, and Gonzales. Rod Laver's in 1969 thus stands as the only undiminished Grand Slam by a male.
 
Only Stan Wawrinka among the men, having won Australian Open 2014, can achieve a Classic Grand Slam this year. Stan's excellent clay-court ability, seen at Monte Carlo 2014, suggests that a triumph at Garros 2014 is a serious possibility. If that happens, we can expect widespread talk about his chances for sweeping all four 2014 Slams. An appealing thought is that Wawrinka or in another year one of the Big Four members could become the one to match Laver's supreme achievement of 1969.
 
It is worth mentioning that prior to his four Slam victories of 1938, Don Budge won both Wimbledon and the U.S. crowns in 1937. Since then, no other male player has won six consecutive Slams.
 
Career Grand Slams
 
Only seven males have won all four Slams at least once during their career. Four of them attained their Career Grand Slams as amateurs prior to the Open era -- Perry and Budge in the 1930's, then Laver and Emerson three decades later. Andre Agassi completed his by winning Garros 1999. The sixth and seventh came in recent years -- by Roger Federer at Garros 2009 and Rafael Nadal at Wimbledon 2010.
 
Djokovic needs only a triumph at Garros to become the eighth to achieve the Career Grand Slam. With several strong years probably ahead, his chances to do so seem good, as he has reached the Garros semis on five past occasions including in 2012 when he was tournament runner-up.
 
Federer and Nadal are close to winning each of the Slams twice -- Federer needs another Garros triumph, Nadal needs another at Wimbledon. Only Laver and Emerson among males have already achieved this distinction.
 
Three-Quarter Grand Slams
 
Three members of the current Big Four have won three Slams in a single calendar year but did not win the fourth (a Three-Quarter Grand Slam). Federer did so three times (in 2004, 2006, and 2008, lacking Garros in all three cases), Nadal once (in 2010, lacking Australia), and Djokovic once (in 2011, lacking Garros). Eight other males previously achieved Three-Quarter Grand Slams.
 
A DIFFERENT MEASUREMENT -- COUNTING #1 FINISHES
 
Our Slam and Grand Slam reviews, employed above, contain a glaring weakness, mentioned earlier. Prior to the Open era, professionals were excluded from playing in the Slams (as well as from other "amateur" events). Thus, for example, Roy Emerson stands ahead of Rod Laver in this measurement of career greatness -- a clear distortion. Emerson was a superb player, two years older than Laver, who defeated Laver to win the Slams in both Australia and U.S. in 1961 and became runner-up to Rod at three of the four Slams in the Rocket's Grand Slam year 1962. Rod turned pro late that year, and it was during Laver's absence as a pro when Roy won ten more Slams. But upon Laver's return at the dawn of Open tennis, Emerson won no more Slams, while Laver added five to his earlier total.
 
We therefore turn to a different way of measuring career greatness -- by counting not Slam triumphs but rather how often each megastar achieved the world #1 position at year's end.
 
For constructing our tally we employ two different schemes. For the Open era, each year's #1 player is the one atop the ATP world rankings -- i.e., the product of the ATP ranking-point system upon its installation. But for the pre-Open era, we make a relatively straightforward judgment, choosing our #1 player each year between that year's #1 amateur and #1 professional. In deciding on the top pro and in making the final comparison, we consult various historical studies. (These sources are primarily the chapters on early pro tennis published here starting in October 1999 and now found in the Archive of this column, along with Joe McCauley, History of Professional Tennis, 2000, The Bud Collins History of Tennis, 2008, and ATP and WTA Media Guides, 2013.)
 
Our resulting tally differs substantially from the Slam count. The rankings of several stars of the pre-Open era are improved, and those of most later performers are generally diminished. (We start at year 1913, and we exclude the years of world wars.)
 
Year-end #1 Finishes
Bill Tilden and Richard Gonzales, each 7 times
Rod Laver and Pete Sampras, each 6
Jack Kramer, 5 1/2
Roger Federer and Jimmy Connors, each 5
Ivan Lendl and John McEnroe, each 4
Ken Rosewall, 3 1/2
 
Thus Rod Laver moves upward to join the highest few, mainly by his success after turning pro. Perhaps surprisingly, in our analysis Laver's credentials as #1 amateur in 1961 were less compelling than those of #1 pro Rosewall. Rosewall's and Laver's were deemed equal in Rod's first Grand Slam year, 1962, and when Laver and Rosewall both competed as pros in 1963, Rosewall became again our sole #1. All of Laver's solo #1 finishes came later.
 
Roger Federer, our leader in the Slam count, here slips behind five others. Three of those here ahead of Roger -- Kramer, Gonzales,and Laver -- scored their #1 finishes mainly as pros in the pre-Open period. Pete Sampras too scores ahead of Roger here, though Pete never achieved the Career Grand Slam. Federer -- tied here with Jimmy Connors in sixth place -- becomes the only still-active player in our top ten.
 
Has our method led us to judge the champions of the pre-Open period too generously, thereby downgrading the later champions?
 
It is striking that among the super-champions of the Open era, identified by the official and highly objective point system, achieved their years as #1 almost entirely in uninterrupted runs. All six of Sampras's #1 finishes came in succession 1993-1998, and Federer's five years of triumph all came in a six-year period 2004-2009, as did all five of Connors 1974-1978, and all four of McEnroe's 1981-1984 . Meanwhile Lendl's four came in a five-year period. That each of these megastars maintained dominance over a largely unbroken period is clear.
 
Meanwhile our evaluations for the pre-Open period also show sustained runs of domination by the megastars. Rod Laver's total here of six #1 finishes consisted of five consecutive #1 finishes 1965-1969 preceded by two shared ones, in 1962 and 1964. Gonzales's seven came in six consecutive years 1954-1959 plus shared years 1952 and 1960. And Kramer's 5 1/2 all came during seven years 1947-1953.
 
That the super-champions of both pre-Open and Open eras display multi-year sequences of dominance tends to support the validity of our pre-Open method.
 
What of Nadal and Djokovic in our tally of #1's?
 
Rafa and Novak both rank within a group just behind the first ten. Rafa shows three #1 finishes, none of them in consecutive years. Novak finished as #1 twice -- in 2012 and 2013. Both Rafa and Novak are young enough to surpass the other group members, among them Budge, Perry, Newcombe, Vines, and Cochet.
 
Note that among the ten most-frequent #1 finishers listed here, the median age of finishing as #1 was 27 1/2 -- roughly the current ages of Rafa, Novak, and Andy Murray and therefore supporting their likelihood of further crowns.
 
DUAL AND TRIPLE MONARCHIES
 
Has the unusual strength of the Big Four retarded each member's chances for dominating in our measurements?
 
It is sometimes said that the existence of very strong contemporary opponents tends to produce the most distinguished megastars. The list of past Career Grand Slam winners supports the point, as among the seven are three pairs of contemporary rivals -- Budge-Perry, Laver-Rosewall, and Federer-Nadal. The seventh Career Grand Slammer, Andre Agassi, also over many years faced a signature contemporary rival. That was Pete Sampras, who ranks among the leaders on our two primary lists here but never captured Garros. The phenomenon is also recognizable in women's tennis.
 
If dual monarchies have been repeatedly seen in tennis history, our study of #1 finishers also shows extended periods of triple monarchy:
 
Longest Triple Monarchies
Kramer, Sedgman, and Gonzales, twelve #1 finishes in twelve uninterrupted years (1948-1959)
Tilden, Lacoste, Cochet, twelve #1 finishes in twelve uninterrupted years (1920-1931)
Connors, Borg, McEnroe, eleven #1 finishes in eleven uninterrupted years (1974-1984)
Federer, Nadal, Djokovic, ten #1 finishes in ten uninterrupted years (2004-2013)
 
Unquestionably the Big Four have been an extremely strong group at the top of men's tennis. But in their long domination, our own times are not unique.
 
THEIR PLACES IN HISTORY
 
Roger Federer as expected emerges from our survey with superior credentials for inclusion among the very few atop tennis history. His leadership in Slam triumphs seems safe for many years, and he remains near the top in #1 finishes. He has achieved the Three-Quarter Grand Slam three times, and is one tournament away from achieving the double Career Grand Slam. All this came in an era of great strength among his contemporaries, seen in the existence of the long-standing Big Four and the yet unbroken triple monarchy of #1's. For myself, Roger has already achieved equality with Laver as greatest of them all.
 
But remarkably, Nadal at 28 remains within plausible range of surpassing Federer in our measurements, provided that Rafa can sustain his high level for several more years. Djokovic is farther back but, being a year younger than Rafa and perhaps less worn physically, Novak could pass Rafa. If any player finishes his career close to Roger in our measurements but including a Classic Grand Slam, our vote would probably belong to him.
 
MEGASTAR -- SERENA WILLIAMS
 
The recent domination by the Big Four in the men's game is contrasted by a domination by a single player among the recent women. Serena Williams has achieved by far the most Slam triumphs among active women -- a total of seventeen, placing her sixth on the women's career list, close enough for fast movement several places upward.
 
Career Slam triumphs
Margaret Smith Court, 24
Steffi Graf, 22
Helen Wills Moody, 19
Martina Navratilova, 18
Chris Evert, 18
Serena Williams, 17
Billie Jean King, 12
 
We last reviewed the greatness of Serena and her chances for further honors in late 2013 when we chose her our Woman of the Year. We then noted that among the five superstars yet ahead of her on the Slam-triumph tally, few had won Slams beyond Serena's age of 32. The oldest Slam winner among the superior group was Martina Navratilova, who won Wimbledon at age 34 after two years without a Slam crown. Thus despite Serena's stated wish to surpass Margaret Court's all-time total and despite Serena's dominance during 2013, Serena's chances for many new Slams seemed weak.
 
Then in early 2014, seeking a sixth triumph at Australian Open, Serena reached only the final sixteen, losing to Ivanovic in a split-setter. She had won the earlier tune-up at Brisbane, and she later won the Premier Mandatory at Miami, where she defeated both Sharapova and the recent Australian winner Li Na. A first-round loss at Charleston began her clay-court season. But Serena has often shown recent poor results to be meaningless at the start of the next Slam -- in this case Garros 2014.
 
Besides Serena, four other women still actively competing in singles have won two or more Slams. Venus Williams has won seven Slam crowns, Maria Sharapova four, and Victoria Azarenka and Li Na each two. All are well behind the seventh-place holder, Billie Jean King, who won twelve singles Slams. Several years of dominance and Slam-winning are possible for Maria, now 27 or Vika at 24. But the age of Venus at 33 and Li Na at 32 persuasively limit their chances for significant rise in the primary measurements used here.
 
Grand Slams
 
Three women in tennis history have achieved Classic Grand Slams. American Maureen Connolly was the first, losing only one set in sweeping all four Slams in 1953. Later winners of the Classic Grand Slam were Margaret Smith Court in 1970 and Steffi Graf in 1988.
 
The Classic Grand Slams of both Connolly and Court were parts of longer runs reaching six consecutive Slam triumphs. Martina Navratilova also won six Slams consecutively -- three in 1983 and three in 1984. Other winners of Non-Calendar-Year Grand Slams were Steffi Graf in 1993-1994 and Serena Williams in 2002-2003.
 
A total of twelve women have captured the Career Grand Slam. Two remain active -- Serena Williams, who completed the task by winning Australian Open 2003, and Maria Sharapova, who completed at Garros 2012. Especially remarkably, Steffi Graf won each of the four Slams four or more times, Margaret Court did the same three times, and Navratilova and Serena Williams each twice. High performers of recent years who won three of the Slams careerwise but not the fourth were Hingis, Davenport, and Venus Williams, all of whom lacked Garros, and Henin, who never won U.S. Open.
 
Counting Women's #1's
 
More vexing than the past exclusion of pros from Slams is the often limited participation in the Australian championships by top women from other lands. Australian players won 43 of the 53 Australian championships played prior to 1979 and also scored many runner-up finishes. But since then, only once has an Australian woman reached the final round. That was Wendy Turnbull, runner-up in 1980.
 
Our counting of #1 finishes is only slightly distorted by this difficulty:
 
Year-end #1 Finishes
Helen Wills Moody, 10 times
Steffi Graf, 7 1/2
Margaret Smith Court and Martina Navratilova, each 7
Suzanne Lenglen and Billie Jean King, each 6
Chris Evert, 5
Margaret Osborne du Pont and Lindsay Davenport, each 4
Serena Williams, Maureen Connolly, Justine Henin, and Martina Hingis, each 3
 
Most of the leaders in the Slam list are also seen here. Steffi Graf is second in both tallies. Graf's reign was interrupted by Monica Seles, but Steffi resumed her domination during Monica's long recovery from stabbing and largely maintained it after Seles returned. The long reign of Helen Wills Moody began when Lenglen turned pro and soon ceased competitive play. Given Suzanne's temperament and considerably greater age, Moody's tallies in Slams and #1 finishes would probably have been only slightly lessened had their short rivalry continued. Margaret Court, whose 24 Slams included 11 Australian crowns, ranks in #1 finishes well below her top place in the Slam count.
 
Serena's Place in History
 
Serena is well back in both Slam triumphs and #1 finishes, and her chances of reaching first place in either measurement are negligible. She could rise several places in both, however, thereby confirming what seems her rightful place among the very few near the top. Her double Career Grand Slam and her Non-Calendar-Year Grand Slam help in raising her credentials here.
 
As for Sharapova and Azarenka, both are young enough for considerable further success. But physical problems that have troubled both women of late suggest that their further penetration on the all-time lists, though perhaps significant, will be less than drastic.
 
DOUBLES
 
The men's Big Four plus Serena Williams have provided five main protagonists here. We now add the final increment -- two doubles superstars, a pair of brothers still active in the pro doubles wars, who have already surpassed all other male pairs in modern tennis history in their Slam doubles conquests.
 
Slam Crowns, Men's Doubles
Bob and Mike Bryan, 15
John Newcombe and Tony Roche, 12
Todd Woodbridge and Mark Woodforde, 11
 
The Bryan twins emerged from top-level junior play and then Stanford University in 1998, where the team twice won the NCAA championship and where left-handed Bob won the NCAA singles and, with brother Mike, the doubles in 1998. As pros they quickly showed themselves a potent doubles pair, first attaining the world's top ten in 2001. The partnership remained unbroken, both members relinquishing singles ambitions. Their manner of play introduced a highly active aggressiveness and teamwork accompanied by excellent quickness and power, creating a doubles style unique for the times. Watchers enjoyed their bouncy manner between points and celebratory chest bumps. They have been Davis Cup regulars, and they have been nine times the world's year-end #1 doubles pair.
 
The Bryans equaled Newcombe-Roche by winning their 12th career Slam at U.S. Open 2012 and surpassed them by capturing the first three Slams of 2013. The twins missed a Classic Grand Slam in that year by losing a split-setter in the final round at U.S. Open. That would have been history's second-ever in men's doubles, the first having been achieved by the young Aussie pair Sedgman-McGregor in 1951.
 
Note that reliable data for doubles play among the pros in the pre-Open era are too fragmentary for a valid count of #1 finishes in doubles.
 
No current women's doubles pair threatens the all-time mark of twenty Slam crowns, attained by pros Navratilova-Shriver in the 1980's and also by amateurs Brough-Osborne three decades earlier. Serena and Venus Williams have competed often enough to win thirteen doubles Slams to date, in fourth place on the all-time list. Nor does there seem any likely pair to join Navratilova-Shriver in achieving the Classic Grand Slam, theirs of 1984 being the only one in women's doubles so far.
 
WHERE WE ARE
 
There is no doubt that the brand of tennis played by today's top pros surpasses the game played in earlier decades -- a product of the larger population of determined young players nowadays, the advanced techniques and training methods now understood widely, and the moneys now having entered the sport. Here, however, these considerations have entered our discussion only peripherally.
 
We have seen that relative to their contemporaries today's male megastars have followed patterns of dominance fairly similar to those of their most distinguished predecessors. Federer, Nadal, and Djokovic all face tantalizing chances for climbing higher. Meanwhile successive eras continue to unfold. Already on the scene are the apparent leaders of a new tennis generation -- Nishikori, Raonic, and Dimitrov. Indeed, those of a still newer generation are coming into focus -- perhaps the Australian teenagers Kyrgios and Kokkinakis.
 
Similarities between current women's tennis and that of earlier times are cloudy. Dual monarchies have prevailed historically among the women -- e.g., Lenglen-Moody, Court-King, Evert-Navratilova, and Graf-Seles. But no clear dual monarchy has emerged in among recent women. Meanwhile no woman in the 21st century has achieved more than two consecutive #1 finishes, and the current women's field has produced only one current singles megastar, against four deemed here among the men. Probably the phenomena indicate a prevailing population of neither unusually strong nor unusually weak female stars. Instead, the amorphous recent times have resulted from frequent cases of injury, sickness, or early retirement among the top women.
 
-- Ray Bowers, Arlington, Virginia, U.S.A.