Roddick enjoys studying the vital stats

Andy Roddick is a man who loves to check out vital statistics - and that has nothing to do with his swimwear model wife.

The American was poring over a sheet of stats relating to his 7-6 7-6 4-6 6-3 victory over Austrian Juergen Melzer in the Wimbledon third round on Saturday when he walked into his news conference and was asked to explain what he looked for.

"First serve percentage is big for me. Points won receiving second serves is big for me. And the other one is just feeding my curiosity," the sixth seed said.

"(The stat sheet) rarely lies. I mean, I can normally guess. As far as first serve percentage, I can normally guess (within) two or three per cent. You kind of get a feel for it."

The key numbers against the Austrian 26th seed would have made pleasant reading - Roddick got 72 per cent of his first serves in and fired 33 aces at the left-hander.

He was frustrated not to have found a way to break Melzer in the first two sets, when games went with serve, but was pleased with the way he handled the tiebreaks.

"I think my career record in breakers is pretty good. I feel comfortable obviously, being able to win cheap points under tense situations with my serve helps," said the 26-year-old, who married model Brooklyn Decker earlier this year.

The American's previous two matches had also gone to a fourth set and, with dark rain clouds gathering above, Roddick was keen to get things over with quickly before the new Centre Court roof could be deployed for the first time in a match.

He had to break twice in the fourth but eventually secured victory with an ace.

"Like the other two matches, I wish I could have converted on a chance in the third set. But probably I hit the ball my best in the fourth again," the 2003 US Open champion said.

Roddick, Wimbledon runner-up in 2004 and 2005, today plays against Tomas Berdych.

Meanwhile, Roger Federer will have happy memories of his last encounter with Swede Robin Soderling at Roland Garros and will be hoping for a similar outcome when he opens the play on Wimbledon's Centre Court today.

The Swiss master swept past Soderling to clinch his 14th grand slam title earlier this month, a performance so convincing on what is statistically Federer's weakest surface that the 27-year-old is a big favourite to reach the last eight.

Andy Murray will again play last on the main show court against 19th seed Stanislas Wawrinka, while in between stands an interesting duel between women's world number one Dinara Safina and former Wimbledon champion Amelie Mauresmo of France.

Over on Court One holder Venus Williams, chasing a sixth title at Wimbledon, starts proceedings against Serbia's Ana Ivanovic, then Spain's number seven seed Fernando Verdasco is next in the firing line for Croatian ace-machine Ivo Karlovic.

Serena Williams finds herself on Court Two where she faces the unseeded Daniela Hantuchova, of Slovakia. That match is followed by former champion Lleyton Hewitt against Radek Stepanek.

Novak Djokovic is the latest top four player consigned to an outside court. The 2008 Australian Open champion plays Dudi Sela, of Israel, on Court Four.