KEY BISCAYNE, Fla. -- The Nasdaq-100 Open quarterfinal between Andy Roddick and Carlos Moya was won in the mind.
Serving for the match Thursday afternoon, Moya missed a pretty easy volley that changed the momentum: Roddick advanced to the semis with the 5-7, 6-2, 7-5 victory.
"He game me a gift of a game when he was serving for it at 5-4," Roddick said. "I would love to sit here and claim credit for it and say I was just fighting, and I was great and everything, but that's not really the case."
"It's very disappointing and frustrating," Moya said, "you know, to be out there for two hours and the most important game of the match, and do what I've done today. I mean, I have no words to describe how I feel."
On Friday night (ESPN2, 7 ET) in the semifinals, Roddick will play fellow American Vince Spadea, who also knows how powerful the head game is out on the court.
Spadea, 29, holds the dubious honor of having the longest losing streak on the ATP Tour -- 21 consecutive matches. By the end of 2000, the former top-20 player's ranking had dropped to 229.
Spadea no longer enjoyed his job. The training and lifestyle had become an ordeal. ("Even your rest periods are planned out," Spadea said.) He took a "bit of a sabbatical without the pay," he says, to figure out what he wanted his life in tennis to be.
One option was to continue his journeyman style of play, going country to country as a challenger, not a winner. That choice, Spadea admits, would have prolonged his stagnation.
"I was just kind of doing things 50 percent, and 50 percent is not good enough in the challenger circuit -- or even 80 percent," Spadea said. "So I needed to go 100."
To that end, he began working with sports psychologist John Murray. At first, they met two or three days a week in Murray's office in Boca Raton, Fla. As Spadea began to travel, the two would speak over the phone and still meet when possible to plan out goals. At one point, Spadea began to think in terms of progressive steps forward. For example, in two or three tournaments at a time, he would aim for the quarterfinals or semifinals.
By the end of 2001, he won a challenger in Houston, defeating James Blake and Mardy Fish along the way.
"That was kind of a time where I really started to see the light in terms of my intensity and my level of play and the fact that I thought maybe I could come back to this level that I'm at -- or the level that I was," Spadea said.
In 2002, he finished inside the top 100 and reached the third round at the French Open -- his best Grand Slam appearance ever. Spadea finished 2003 ranked in the top 30 -- not quite where he was but better than where he'd been.
"Using a sports psychologist helped me just kind of, you know, clear my mind, learn some new concepts, you know, remotivate my level of just the way I wanted to train," Spadea said.
"I'm overjoyed with his success because of how hard he's worked," said Murry, who says he's worked with over 30 tennis players during the past five years, though due to confidentiality concerns it's difficult to verify whom.
Spadea, who in early March began working with coach Sam Aparicio in Scottsdale, earned his first career title there this year. And the guy he beat in the semifinals just happened to be Roddick, who is now struggling with his own mental block.
"I think it's just all year I felt like I'm on the verge of playing really well," Roddick said. "It's just kind of -- I can feel it coming on, but it's not quite there. Maybe I'm trying to force a little bit too much."
Since the U.S. Open, Roddick has won only one tournament -- San Jose. He's putting up good results, reaching semifinals, just not lifting as many trophies as he expected to. Roddick said that in Scottsdale he was up a set and a break, but he let the match get away.
"He's just playing great tennis right now," Roddick said of Spadea. "He's putting on his hard hat; he's going to work. He's not flashy. He's not going to make the crowd 'ooh' and 'ah,' but he's gonna make you beat him."
"He's got a big serve and, you know, my return happens to be one of my better shots, so that creates a good matchup," Spadea said of Roddick.
Both men say it's important to be able to win even when you're not at your best.
"My game has gotten better because I can hold serve, I can hit winners when I need it and at crunch time," Spadea said. "Whereas before, I would either win easy or kind of wither away. If things were going well, no matter what your cylinders are made up of, you're going to be successful for that moment."
It's an important step toward becoming a champion, to be able to win on days when you just can't get into the zone.
"That's where you can kind of judge your improvement," Roddick said. "Most people can win when they're really playing well."
Cynthia Faulkner is the tennis editor for ESPN.com.