Originally Posted by Mustard
Gottfried von Cramm was a huge underachiever. He won 2 French Championships, but was 3 times runner-up of Wimbledon, a runner-up of the US Championships and lost a decisive Davis Cup match to Don Budge. Then he was jailed for a year because he opposed the Nazis, so they nabbed him on a homosexual activity charge. Soon after getting free, von Cramm won 1939 Queen's Club by beating Bobby Riggs (who would be that year's Wimbledon champion) 6-0, 6-1. Von Cramm was then scandalous banned from 1939 Wimbledon by the All England Club due to that homosexual activity conviction, and the US authorities followed suit before the 1939 US Championships, refusing him a visa.
Those losses in the majors and in Davis Cup are not really signs of underachievement. He did the best he could at those events. The other stuff is true though. He underachieved due to external circumstances.