WIMBLEDON, England -- Mardy Fish was scuffling along in a first-set tiebreaker against Denis Istomin on Wednesday when he hit two beautifully pure forehands. They barely skimmed over the net, skidded off the emerald grass, and stayed low and nasty, like a Zack Greinke slider.
Istomin couldn't handle either of them, blasting both balls into the net as forward-thinking Fish closed in. The accounting people called them unforced errors but, make no mistake, they were forced. Ultimately, Fish won 7-6 (6), 6-4, 6-4.
If it's May in Paris, someone is sure to write the story: Americans+clay = oil+water. The grim statistics are cited, the usual reasons given.
Now that it's June in London, there is a completely different equation: Americans+grass = peanut butter+jelly.
It's kind of odd, actually. Grass is the surface Americans play on the least -- maybe for a few weeks a year -- but, for a number of reasons, it's the surface that best suits their games. Men and women from the United States seeking the French Open championship are riding an oh-for-18 streak; the Williams sisters, meanwhile, have won six of the past eight titles at Wimbledon and have been in 10 of the past 11 finals.
"We've got some good power players," said Patrick McEnroe, USTA general manager of player development. "It's always been part of our M.O. Americans are naturally aggressive. Big serves, big shots are rewarded more on grass than any other surface."
The lush, living lawns of the All England Club have been Americans' private garden for years:
" Pete Sampras won here seven times, constituting half of his Grand Slam singles titles.
" Andy Roddick's lone Grand Slam singles victory came at the U.S. Open, but he has won two more matches at Wimbledon.
Once, grass was the fastest surface in tennis. But after Goran Ivanisevic and Patrick Rafter turned the 2001 final into an ace-fest, Wimbledon slowed things down. The original mix was 70 percent rye grass and 30 percent creeping red fescue, but now it is 100 percent rye. Because rye sits up higher than fescue, the greater friction slows the ball down. Plus, players say, the balls are bigger today than they've ever been. The result is a higher bounce than before -- but still the lowest bounce among the Grand Slams.
But although some hard courts play faster, grass places a greater premium on the serve -- and the service return.
"The serve -- even after they slowed things down -- is probably the most important factor," McEnroe observed. "The ball doesn't go faster, but it goes lower. That means instinct comes into play, plus athleticism.
"If Roddick puts it in the same spot on grass [as on a hard court], it's not going to come back as often."
Roddick's former coach Brad Gilbert put it this way: "Hitting a ball at your knees is a lot harder than hitting it at your waist. That's why there are more free points on serves on grass than on any [other] surface. If you can serve here, you've got a chance."
The best Americans have always had big serves.
That's what brought Sampras those seven titles. It's why Roddick got to three Wimbledon finals. It's the signature shot of both Venus and Serena. Last year, you might recall, John Isner set the record for aces, 113, against Nicolas Mahut in the longest-ever match.
In the early going this year, U.S. players have been their typical, hard-serving selves. After one match apiece, Roddick and Fish were among the ace leaders with 30 and 26, respectively. Venus has 19 aces in two matches, leading all women, and Serena was No. 1 with 13 aces after her first match.
Venus' 12 aces Wednesday might have been the difference in beating Kimiko Date-Krumm in three sets that stretched nearly three hours.
Like many of the leading Americans, Fish has played best on grass in his career. His 40-24 (.625) mark is appreciably better than his 179-120 (.599) hard-court record. He played three grass events in succession last year -- Queen's Club, Wimbledon and Newport -- reaching the final at Queen's and winning Newport, taking 11 of 13 matches.
"I feel most comfortable with my style of play on this surface," Fish said after his first-round win over Marcel Granollers. "I feel comfortable coming to the net; I feel comfortable coming forward. They're doing a really good job of making it tough to do that. When the sun's not out, it's very hard to get the ball through the court -- minus the serve."
Indeed, Gilbert said, when you take the serve and return out of play, the rallies here at Wimbledon actually tend to last longer than they did at the French Open, where harder, smaller balls picked up the pace.
"At Roland Garros, there was a lot more one-two tennis," Gilbert said. "Here, it's tough to end the points. It can get monotonous."
Fish, like most Americans, plays on the baseline, takes the ball as early as he can and hits hard, flat shots. This results in more of those low, skidding shots -- as opposed to the typical clay-court players with loopy swings who stand five feet behind the baseline. No. 1-ranked Rafael Nadal, perhaps the best clay-court player ever, adapted this baseline style, and he's been to the final here the past four times he has played.
Not every clay-courter has made the adjustment.
Juan Ignacio Chela of Argentina -- a two-time Grand Slam quarterfinalist -- was playing six, sometimes seven feet behind the baseline in his second-round match against Alex Bogomolov of the United States. The American won the first nine games. And prevailed, surpisingly, in three sets.
Swift serves. Bold strokes. Fast-forward play. For Americans, the grass is almost always greener at the All England Club.
Greg Garber is a senior writer for ESPN.com.