Are you taking into account the field? I don't think Laver's year in 1962 should be considered. Rosewall's seasons in 1962 and 1963 were excellent but what competition did he have in those years? Gonzalez was gone in 1962 and Laver wasn't there yet. In 1963 he had an inexperienced Laver but I guess you could say that with any tour with a new pro. However I do feel Rosewall's competition in those years weren't as high as that of the 1950s when Kramer and Gonzalez were number one over greats like Sedgman, Segura, Hoad, Rosewall, Olmedo, Trabert, Budge, Riggs and of course each other.
Gonzalez in my opinion had a number of superior years to Rosewall's best year. For example in 1958 he won the Tournament of Champions, the US Pro and the World Championship Tour over Lew Hoad. Tilden in 1920 Won the only two majors he entered with Wimbledon and the US Nationals. In 1956 Gonzalez won two Pro Majors and was in the finals of the other, won the Tournament of Champions and also defeated Tony Trabert by a crushing margin in the World Championship Tour. That's basically winning five majors!
In 1930 Tilden won Wimbledon, the championships of Germany, Italy, the Netherlands (Dutch Championships) with 18 tournaments won in a year he would be 37. A number of his years in the early 1920s are to be considered also.
Connors in 1974 I believe had a super year in winning three majors out of three, the US Clay courts over Borg, the Pacific Southwest and the South African Open over Ashe.
Borg in 1978 and 1979 had incredible levels of play.
John McEnroe in 1984 won Wimbledon, the US Open, was in the finals of the French, won the Canadian Open, US Pro Indoor, the Tournament of Champions over Lendl and the year end Masters over Lendl.
If you count the amateurs then Sedgman in 1952 and Trabert in 1955 are viable as is Hoad in 1956 but I wouldn't count them.
I am going back to the beginning of this thread. A question was asked and we got off-topic. To offer a possible answer to the question of years of "greatest accomplishment," I put "accomplishment" in a vacuum, not allowing questions of relative level of competition to enter into my evaluation.
Using this simple approach, and also leaving out the obvious calendar Grand Slams (traditional) of Budge and Laver, here, chronologically, are the years of greatest "accomplishment" - greatest accomplishment w/o a calendar-year Grand Slam.
Tilden ’21: Wimbledon and U.S. again and world clay-court champ by winning World Hard Courts Championship, led successful Davis Cup defense;
Tilden '25: Credited with a 78-1 record en route to 15 titles, sixth straight U.S. Championship and sixth straight Davis Cup triumph, with a final round hat-trick;
Budge ‘39: beat pro Champ Vines in WCS, and convincingly in ancillary tour, and thumped Perry in another tour; won both Pro Slams entered (London and Paris).
Trabert '55: Three of four amateur Majors, 106-7 record and 18 titles.
Gonzalez ’56: Beat Tony Trabert 76-25 on WCS tour; won three of four Pro Slams (counting TOC), and finalist in fourth.
Gonzalez ‘57: Beat Ken Rosewall by 2-1 margin in WCS tour; won two of three Pro Majors played that year, plus Masters Pro Round Robin.
Rosewall ’63: Won the Pro Grand Slam, plus a six-man WCS tour.
Laver ‘67: Pro Grand Slam plus Wimbledon Pro, a fourth Major according to many, and 19 total titles;
Connors 1974: 99-4, three Majors out of three he played, 15 titles.
Vilas '77: Not sure about this one, but an 80-Plus consecutive match winning streak when we (rightly) throw out the ridiculous Nastase spaghetti-racket caper.
Borg ‘
79: 16 titles (13 official ATP tournaments plus three non-sanctioned events against his top rivals) on 84-6 official record (but more like 95-6), including two of three Majors entered, four
Grand Prix events and the YEC.
McEnroe ‘
84: 82-3, 14 ATP titles (plus two non-sanctioned titles, which improves his record to 88-3), better than 22-1 versus top-10 players; two Majors out of three entered and fifth-set loss in the third Major, plus titles at both WCT
and YEC.
Pick what you like of Federer, I'll take:
Federer 06’: 92-5; 12 titles, including three of four Majors and finalist at French Open, four Masters 1000s, including coast-to-coast double and YEC. Lost only to Nadal (4) and Murray
Nadal ’10: This one sneaks up on you. Only 71-10 record, but won three Slams on three surfaces, clay, grass and hardcourt.
Djokovic ’15: 82-6, 11 titles, including three of four Majors and finalist at French (and played very good match), a record six Masters 1000s, including his third coast-to-coast double and a fourth Italian championship, and the YEC.
Thinking purely accomplishment, without regard to level of competition, I would have to say
Nole's 2015 (I actually think his 2011 is more impressive when competition factored in), followed by
Mac's '84,
Tilden's '25,
Gorgo's '56 and
Connors' '74 as top five on paper. When you drill down, you will get a different result. But the way I understood the question it was just objective accomplishment.
There are other great years out there: Tilden '20 and '30; Cochet '28, Perry '34, Kramer '47; Hoad '56; Rosewall '62; another three for Laver; Borg '80; Lendl '86 or '87; others for Fed; Nole's 2011, as mentioned. But none of them are quite so dominating as those I put up, IMO.
Interested in your thoughts - these are just ideas.