Riggs was not, in my view, unfortunate the war came along. He was fortunate (in tennis terms) because after the war, Budge was not the same player. In 1942 Budge enlisted and in 1943 Budge tore a muscle in his shoulder while on an obstacle course and he was not the same player after that. Budge would have beaten Riggs in 1946 World series had it not been for the war (Budge very nearly beat Riggs on the 1946 tour anyway). Riggs himself said "after the war Budge took something off the ball and played his shots safer. I could play against that kind of game". Let us not forget, in their last tour before war service, 1942, Budge came out on top comfortably. Of course, Budge would have eventually declined (maybe Kramer, 6 years younger than Budge and in his prime, would have just got the better of Budge in 1948 World series if the two had played).Another great champion (even if lower level than Kramer) is Bobby Riggs.
If we consider only Post War II period Riggs is the best player in 1946 (even if with a small margin on Budge) and 1947 (with small margin on Budge and Kovacs).
Then Kramer explodes.
But it is intriguing that probably Riggs may have been the best player during the war.
Wikipedia reports that Ray Bowers wrote "The Limited Tennis Activity Over The Last Three Years Of The War dictates a single ranking list covering the entire period" he ranked the best eight players in the world for the entire 1943-1945 period : 1. Riggs, 2. Budge, 3. Parker, 4. Kramer, 5. Kovacs, 6. Van Horn, 7. Quist, 8. Petra.
IMHO I don't believe in the 3-year ranking that the writer proposes, there were few matches and it is impossible to understand who were the top players even if Riggs would have raged in the absence of the war.
Riggs has two misfortunes:
1) has Rosewall syndrome, that is not considered a great because he starts to win when Budge is coming down the hill and Kramer is too young (like Rosewall with Pancho and Laver) .. among other things also as a game Riggs and Rosewall seem to resemble (service not sublime but great technique and speed in travel)
2) the war definitely takes away many titles / tours to Riggs (but also to Budge and Kovacs)
Finally, even Rigg,s as Kramer, is unclassifiable even if the level reached by Bobby suggests that he can be placed between 15-20
My ranking Post War II
(Kramer unclassifiable, almost certainly the best player in history, Riggs unclassifiable, suggests that he can be placed between 10-15)
1) Federer T1
2) Laver T1
3) Gonzalez T1
4) Rosewall T1/T2
5) Nadal T1/T2
6) Borg T2
7) Sampras T2
8) Djokovic T2
9) Connors T2
10) McEnroe T2/T3
11) Lendl T2/T3
Riggs was still a great player (Kramer and Budge were two of the best ever and it was no disgrace losing to either). Riggs certainly deserves better than being remembered as an old man that lost to Billie-Jean King. He was much more than that. Kramer said Riggs was very shrewd, but shrewdness only gets you so far if you are playing the likes of Budge and Kramer at their peak, as Riggs found in 1942 against Budge and 1948 against Kramer. When Budge dominated, there was almost no one else who won any of the big titles (after Vines' departure from pro tennis in 1939, Budge was by far the best player). Budge won Wimbledon & US in 1937 (the only 2 slams he played that year), then won the Grand Slam in 1938. He won every World series he played from 1939-42. In major pro events between 1939 and 1942 he lost one match (in 1941 US Pro to John Faunce after returning from illness). So had there been no war, no Budge injury and a full schedule of pro events between 1940 and 1947, it may well have been the case Budge would have won nearly all of them (these were Riggs' best years). Had there been no war, Budge would probably have passed the baton to Kramer and there would have been no era of Riggs being number one. It's speculation of course, but I think that's what would have happened. At least Budge could resume his career after world war 2 unlike poor Joe Hunt.