Will John Isner break through major ceiling or keep bumping head?

John Isner is 13 inches taller than Dudi Sela, but the American was looking up to the Israeli on the scoreboard after their second-round match at Wimbledon. Michael Steele/Getty Images

John Isner played a near-perfect tournament on the grass courts of Newport, R.I., this past week, capturing the title in straight sets. It's a nice table setter for what could be Isner's last best chance to make a major statement at the US Open.

The 6-foot-10 native of Greensboro, N.C., is 32 years old, and just one ranking spot behind the top American -- No. 19 Jack Sock -- following the win. Isner is also entering the sweet spot of his season: the U.S. summer hard court circuit.

"It's been two years since I won a tournament, so I had that weighing on my mind," Isner told reporters after his win in Newport. "It was a perfect week, and I couldn't ask for anything better."

Others, however, have frequently hoped or asked for better from Isner. In the years immediately following Andy Roddick's sudden retirement in 2012, Isner became the spear point of the U.S. men's game -- the guy who could, well, make America great again. But that burden came with ambivalence.

Less than a year after Roddick quit, Isner enjoyed one of his best, most promising weeks. He lost the final of the 2013 Cincinnati Masters to Rafael Nadal, then told reporters, "I never felt like I was a guy who was going to carry American tennis at all. The fact that I ever even made it to the top-ranked American is a huge surprise for me."

Isner's ambivalence has always been evident. Over the past half-decade, he has been a pulsating signal on the radar screen of tennis. He's widely feared and ostensibly capable of anything in a given tournament because of that preemptive, scorched-earth serve. Yet the rest of his game has too often collapsed, and his ability to rise to a challenge has been questioned.

Isner has a hefty 11 ATP Tour titles on his résumé, but all were earned at third-tier ATP 250 events. He has served up big wins, as well as some surprisingly good results on red clay. But he has taken too many puzzling losses to count, most recently this year's four-set capitulation to Dudi Sela in the second round of Wimbledon. The Israeli player, ranked No. 90 at the time, is also 32 -- and a full 13 inches shorter.

Isner has perhaps the most lethal serve in the game, a shot dangerous enough to carry him to great heights (if not to deposit him there permanently). Isner and Nicolas Mahut met in the first round of Wimbledon in 2010, resulting in the longest tennis match ever, with Isner winning the fifth set 70-68. His loss this year in the second round fits a pattern, though, as he has never reached the second week at Wimbledon.

Isner's serve is not quite as lethal on hard courts, but he has fared better at the US Open than across the pond (he reached the round of 16 twice and made one quarterfinal). That's partly because Isner, who treasured his four-year stint at the University of Georgia despite the lure of the pro tour, is a different, better player in the U.S. than overseas. He has confessed to that many times after good wins at home or bad losses abroad.

During a high point of Isner's career in 2014, FiveThirtyEight.com did a deep dive into his statistics. The data showed that Isner won just half his matches outside the U.S., but more than two-thirds at home. To date, Isner has earned only two of his 11 titles outside the U.S. (both at Auckland).

The U.S. summer hard court circuit begins in earnest this week, and Isner can go into it with a full head of steam. He has always been one swing of the racket away from either triumph or disaster, which is often the fate of players who live overwhelmingly by their serves and seek to close out sets in tiebreakers. But it's a little surprising that Isner still hasn't made a deep, resonating run at any major event (that lone 2011 US Open quarterfinal is still his best performance). Can this be the year?

It's a tall order -- but then, Isner is a tall man.