1977 is very debatable. Borg won 11 official titles and went 76-7 on the ATP site. He went 2-1 vs. Connors, with wins at Wimbledon (grass) and the Pepsi Grand Slam (rubico), and a loss at the Masters (indoors) in Jan. 78. He was 3-0 vs. Vilas, with wins at the Masters in Jan. 78 (carpet), Monte Carlo (clay) and Nice (clay). So, Borg was 5-1
versus his primary competition at the top, with 11 titles won, including Wimbledon. He won at Wembley (indoor), Cologne (carpet), Basel (carpet), Barcelona (clay), Madrid (clay), Wimbledon (grass), Denver (carpet), Monte Carlo (clay), Nice (clay), Memphis (carpet), and the Pepsi Grand Slam- Boca Raton (clay). His surface versatility with big titles, head to head record versus Connors and Vilas, and his win at Wimbledon all weigh in favor of Bjorn Borg in 1977. It's debatable, but I would submit that Borg has the best record overall in 1977.