The following is a list of the men tennis players who have the highest overall winning percentages at the U.S. Open in the Open Era. The Open Era began in 1968, when professional tennis players were finally allowed to compete at the four Grand Slam tennis events.
This is an interesting list because two of the highest players on it are active and will be playing in the U.S. Open in 2014. With Rafael Nadal not playing the U.S. Open in 2014, I think either of the active players listed here have a pretty good chance to win the U.S. Open in 2014. A U.S. Open title by either player would move that player to the top of this list.
Tennis players with all-time highest win percentages at U.S. Open (Men)
1. Pete Sampras - 88.7%
With an overall singles record of 71-9, Pete Sampras holds the Open Era record for the highest winning percentage at 88.7%. Pete Sampras won the U.S. Open five times (tied for most Open Era wins) out of the 14 times he competed.
2. Roger Federer - 88.2%
Up until a few years ago, Roger Federer held the record for the highest win percentage at the U.S. Open. That's after he won the tournament five consecutive years from 2004-08.
Overall, Roger Federer has played in 14 U.S. Opens, and has a total record of 67-9, good for a win percentage of 88.2%. If Roger Federer wins the U.S. Open in 2014, he will regain the top spot.
3. Jimmy Connors - 85.2%
Jimmy Connors had a lifetime winning percentage of 85.2% at the U.S. Open, with an overall record of 98-17. That's pretty good considering that Jimmy Connors played in 22 U.S. Opens (he won five of them). It was always fun to watch Connors play in the U.S. Open, even when he was well past his prime.
T-4. Ivan Lendl - 84.9%
Playing in the U.S. Open from 1979 to 1994, Ivan Lendl compiled a record of 73-13, good for a 84.9 win percentage. Lendl won the U.S. Open consecutively from 1985-87, and he made the finals for eight consecutive years from 1982-89.
T-4. Novak Djokovic - 84.9%
So far in his career at the U.S. Open, Novak Djokovic has a record of 45-8, good for the same win percentage of 84.9% as Ivan Lendl. I expect Novak Djokovic to surpass Lendl at the 2014 U.S. Open, and if The Joker wins this year he will be just about at the top of this list.