In some unenlightened circles, tennis is viewed as a "soft" sport.
But though the only contact between combatants usually comes in a handshake at the end, do not underestimate the value of blatant aggression.
Rafael Nadal, whose vulnerable knees forced him to commit to shorter points and takes more risks -- well beyond his protect-and-defend comfort zone -- won all three important North American summer hard-court tournaments on his way to becoming Player of the Year. After he stopped centering the ball and going for the lines, Andy Murray won an Olympic gold medal and his first two Grand Slam singles titles.
"It's not a tactical thing for me," he said last week, while driving between Tampa and Jacksonville. "There were matches where I've been too passive, not breaking serve enough. I need to be more aggressive in those spots.
"I need to understand that making mistakes in my game is not a bad thing at all -- as long as they're the right mistakes. I'm going to try to have an aggressive mindset and stick with it."
Isner lives in Tampa, where the temperature was hovering in the low 70s -- "a little chilly, actually" -- he said, laughing. After turning professional in 2007, following a four-year career at the University of Georgia, the 28-year-old Isner has become one of the game's most consistent players.
How many guys, he was asked, have finished in the top 20 for the past four years running?
Isner started naming names and came up with 10 players. Not bad. The answer is nine -- and Isner is on that list (see chart).
"I'm very, very proud of that fact," Isner said. "I would love to finish in the top 10, but that's not my main focus. If I'm fit and taking care of the right things, everything else will take care of itself."
Isner won 39 of his 63 matches in 2013, titles in Houston (his first on clay) and Atlanta and collected more than $1.2 million, hitting seven figures for the second year in a row. And, likewise, he repeated as the ATP World Tour's No. 14-ranked player.
"Yes," Isner said, "my ranking was exactly the same. One of my main goals every year is to not finish under the ranking of the year before. I've never regressed."
This despite essentially missing two Grand Slams. Isner played a match to open the season in Sydney, losing in straight sets to Ryan Harrison. An injury just above his left knee, where his quadriceps attaches to the knee via a tendon, forced him to skip the Australian Open. Six months later, the same injury knocked him out after the second game of a second-round match at Wimbledon.
His finest moments came in Cincinnati, where in consecutive matches he defeated the No. 10-ranked Milos Raonic, then-No. 1 Novak Djokovic and No. 7 Juan Martin del Potro. Isner lost to No. 3 Nadal in two tiebreakers in the final.
Isner led the ATP in aces for the third time in four years, finishing with 979, ahead of second-place Raonic (883); no other player surpassed 700. Isner also led the tour in break-point saves (71 percent) and tiebreak wins (38) and was second to Raonic, winning 90 percent of his service games.
After losing his second match (to Djokovic) at the Paris Masters on Halloween, Isner went more than a month without swinging a racket.
"I don't like to completely take so much time off, but for me it was the right thing," he said. "I rested my knee a bit and now it's feeling OK. About 10 days ago, I started to get out on the court and work on my game. In the past, I've come back and hit earlier, but I'm at a stage in my career where don't need to hit four hours a day for two months prior to the Australian Open."
His first public appearances after the season came the first week of December when he, James Blake and Justin Gimelstob played in each other's charity events, in New York, New Jersey and Greensboro, N.C. The culmination was a sell-out in Isner's hometown. Proceeds went to the University of North Carolina's Lineberger Comprehensive Cancer Center, where his mother, Karen, was twice successfully treated for colon cancer.
"We had Andy Roddick and the guys, and we had a lot of fun," Isner said. "We raised a lot of money, so I was happy."
Roddick, the last American man to win a Grand Slam singles title and an inveterate jokester, appeared wearing a T-shirt with a photograph of Isner from ESPN The Magazine's Body Issue.
At 6-foot-9, Isner is the second-tallest player among ATP players; Ivo Karlovic is 6-10. Isner, however, is the heaviest, checking in at 236 pounds. Moving all of that weight around can be exhausting, particularly when you are playing a handful of tiebreakers in a major event that requires seven matches. In the Atlanta final, Isner beat Kevin Anderson in a match that featured zero breaks of serve and consumed 2 hours and 54 minutes -- the longest best-of-three match of the season.
Those are precisely the kind of matches that Isner said need to be shortened by being more aggressive.
"I haven't made the second week of a Grand Slam the last two years," said Isner, whose best major performance was reaching the quarterfinals at the 2011 US Open. "My goal is to win those first few matches more quickly and go from there. I'm so big, I wear down faster than most players. Sometimes, I don't conserve enough energy winning those first three, four matches.
"For me, it's being smart."