When he arrived at this week’s Nasdaq-100 Open, Andy Roddick, the defending champion, badly needed a win.

On paper, the first three months of Roddick’s 2005 season looked solid enough: an 18-3 overall record, a Grand Slam semifinal, and a small title in San Jose under his belt. Yet disappointments have far outweighed the young American’s achievements this year. He became unnerved at the Australian Open and fell meekly to Lleyton Hewitt, running his Grand Slam dry spell to five. In the first Davis Cup match of the year, he lost a squeaker to Ivan Ljubicic, 4-6, 6-3, 7-6(11), 6-7(7), 6-2, giving Croatia the upset of the season. Two weeks ago in Indian Wells, Roddick nearly exacted revenge against Hewitt, only to find himself once again outsmarted by the relentless Australian, 7-6(2), 6-7(3), 7-6(4).

Roddick was hoping to right himself this week in Miami, but a wrist sprain forced him to retire in the middle of his second-round match against Fernando Verdasco. Though the injury should only keep him off the court for a week, the world’s no. 3-ranked player has bigger ailments to overcome if he is going to capture more Grand Slams and make a run at the no. 1 ranking.

Only last summer, Roddick and Roger Federer were seen as ideal opponents for the top spot in tennis, with the rest of the field looking on. Even Roddick talked about the importance of defeating Federer to establish a true rivalry. Not only has that two-man race between Federer and Roddick failed to materialize, but Roddick these days finds himself running a distant second along with several other contenders, including Marat Safin, Hewitt, and, more recently, Ljubicic. In coming months, he might fall still further behind as he struggles through the clay court season and the French Open.

Considering all this, one might guess that Roddick is not playing as well as he did when he reached the Wimbledon final last year and won the 2003 U.S. Open. In reality, he is playing as well in some respects – no one serves better than Roddick, and his forehand is among the most forceful on the tour. Yet Roddick’s flawed footwork and tactical blunders are holding him back. Against lesser players, Roddick’s firepower more than compensates for his failings. Against the best, Roddick is often his own worst enemy.

Hewitt, ever patient, continues to show a talent for exposing these weaknesses. This was particularly true in Indian Wells, where their semifinal match turned on very few points.

In the third-set tiebreak, Roddick seized control of a rally and then mishit a routine forehand to fall behind 2-3. He atoned for the error with an ace for 3-3. On the next point, Roddick again found himself in command after firing a deep forehand that pinned Hewitt along the baseline. But Roddick hesitated on his approach, leaving himself in horrible position – around the service line – for his first volley. Point to Hewitt.

Trailing 5-4, Roddick ran around a backhand and belted a forehand into Hewitt’s forehand corner, and promptly admired his shot. There was time to approach, or at least recover his position to create another angle off the scrambling Hewitt’s return. Instead, Hewitt caught the baseline with a floating forehand and Roddick, flatfooted and his racket ill prepared, was left to return the ball off his back foot. The reply was weak and in the middle of the court. Hewitt took over from there and closed out the match.

It is encouraging to see someone who hits as big as Roddick – and does it as often as he does – working hard to approach the net and shorten points. The problem for Roddick is when to approach, and what to do once he does. At times he is too aggressive, running in behind mediocre shots. Other times, he stands around watching good shots, rather than charging. On the way in, he often hesitates or drops his racket face slightly, forcing him to volley with unsettled feet or a racket that is out of position.

Roddick has no trouble taking control of points. Unfortunately, he relinquishes that control just as easily. It is in this regard that he compares most unfavorably to Federer. Once Federer takes command of a point, he rarely has to return to the defensive. This is why players who lack Federer’s firepower – Hewitt and Andre Agassi, to name two – are taking larger risks against the world’s no. 1: They know that if they don’t seize control of a point early, Federer will.

One need only watch Federer’s ho-hum win over Hewitt in the Indian Wells final to understand the difference. In the second game of the match, Federer hit a forehand into the far corner on Hewitt’s backhand side. The approach was no better than Roddick’s in his third-set tiebreaker, but Federer raced in behind it. He struck his first volley well inside the service line and hit it deep, rather than trying for a winner. Hewitt returned the shot, but had no chance to pass. Federer next hit a short volley, causing Hewitt to scurry forward and lift his return into Federer’s strike zone. Having worked to produce a sitter, Federer finished off the point with a clean volley past Hewitt, who was trapped in the middle of the court. Federer later broke Hewitt a second time in the set with similar play.

It’s doubtful that Federer can run much faster than Roddick, but if the two were sprinting, Federer would be out of the blocks before Roddick heard the gun. When Federer approaches, there is no hesitation.

In tennis, creating angles and getting into position is less about speed than about reflexes: instantaneous reactions not just to opponents’ shots, but to one’s own. As he applies pressure throughout a match, Federer can inspire desperation in his opponents, causing them to try increasingly difficult shots. The result, inevitably, is more errors, and more free points for Federer. Against Roddick, there is less reason to despair because the American might well let his opponent off the hook.

Right now, Federer remains the Muhammad Ali of tennis. He can land heavyweight punches, but he would not be the player he is without the best footwork in the sport. If Roddick does not improve in this area, Federer, and the hope for a real rivalry, will remain just out of reach.