This is actually a very good argument. And it can be interpreted multiple ways.
For the second serve, the main idea is to not let your opponent get on the offensive right away and let you set the point up. This means you must rally after you hit your second serve, even if you were aggressive with is. So this means both players must get into a rally after hitting a second serve. And we ALL agree that Roddick's ground game is not nearly as good as Federer's. So all else being equal, Roddick shouldn't even come close to Federer in second serve points won. If they both had the exact same second serve and used it in the exact same way, Roddick should still have a lower winning percentage on second serve points no matter how you look at it. But their percentages are EQUAL! The only rational inference that can be made from this evidence is that something is compensating for Roddick's ground game on second serve points. There are only 2 things that Roddick has in these points: his second serve, and his ground game. If his ground game is weaker than Federer's, his second serve must be stronger. For Federer and Roddick to have the same second serve winning percentages, this is the only plausible conclusion available to us.
Bottom line, this evidence proves that Roddick's second serve is better than Federer. This does not necessarily mean that he uses it better than or even as well as Federer, but the overall quality of his second serve is much better (and apparently so much better that he doesn't need to use it nearly as well as Federer does). If you disagree with my logic, prove me wrong.
Now, as for the first serve, this can be interpreted in two ways. But before that, I'd like to present some new evidence which was either overlooked or excluded by the OP that is terribly crucial for both sides to logically continue this argument with all the facts.
1st Serve Percentage
Position / Player / % / Matches Played
2 / Roddick / 70% / 59
21 / Federer / 62% / 61
http://www.atpworldtour.com/Rankings/MatchFacts.aspx (Stats taken 10/9/09 at 8:06)
For one, we know that a higher first serve percentage will inevitably lead to more aces. However, Roddick's first serve is 13% higher than Federer's (relatively, which means multiply Federer's serve percentage [62] by 1.129 and you'll get Roddick's [70]). If their serves were the same, then we should expect Federer's average number aces per match to be the same as Roddick's if we have the same percentage.
Federer's average ace count in a match is 9.51
Federer's average ace count if his first serve percentage was 13% higher is still only 10.73
Roddick's average ace count in a match is 12.76.
So Roddick gets 2 more aces in the match compared to Federer if their first serve percent was the same. That's not a lot. Even as it is, it's only a difference of 3.25. Meaning Roddick gets an extra 3 free points in a match compared to Federer. But their first serve winning percentages are the same. So what conclusions can we make from that? Well, assuming 100 points will be played on their serve, Roddick will play 70 points on his first serve, and Federer will play 62. From there, Roddick will win 55 of those points, nearly 13 will be from aces. That means Roddick earns 42 points with his first serve after the opponent got a racket on it. Federer will win 50 points on his first serve, and 9-10 will be from aces (we have to round up to make things simple, so it'll be considered 10 from now on). That means Federer earns 40 points on his serve after the opponent gets a racket on it. Even if we increase that number by 13%, it's still only 45 points, a 3 point difference. But we know Federer's overall game and usage of the serve are far superior to Roddick's, yet despite all that he only wins 3 more points using the combination of his serve and ground game in 100 points! Of course this gap will further increase in a longer match, but that's still not that much. Roddick's serve HAS to be better than Federer's for the gap in points won to be so small. And on Federer's average first serve percentage, Roddick wins more points on serve!
No matter how you look at it, Roddick (as it stands right now) will on average win more points on serve than Federer. Of course, these numbers change drastically when Federer's on the receiving end of those serves.
Now, there are some small out of the ordinary happenings that modify these statistics (second serve aces, service winners, blah blah blah). But looking at these numbers, Roddick does a better job on serve even though the rest of his game isn't as good as Federer's. The conclusion is simple: Roddick's serve is better than Federer's. And you consider average serve speed, Roddick's is an extra 10 mph faster and he still maintains a noticeably higher first serve percentage than Federer.
The other way to interpret this is that Roddick has a more powerful serve, or that his overall service game is better. Aside from when someone gets a good return in, I agree. Roddick having a more powerful serve is self evident, but the numbers show his service game is better. Punch in the numbers, Roddick wins more points on serve.
However, I am not saying that playing against each other, Roddick will eventually win because his serve numbers are so great. If they played each other, Federer's percentages would actually go up! And Roddick's would go down! Why? Because Roddick has a terrible return game while Federer's is excellent. Federer makes you play on your serve and he knows how to serve such that Roddick can't make a dent in his serve.
So overall, against other players on the tour, Roddick is the better server if we go by results and numbers. But Federer clearly uses his serve better, and has a better overall game which totally eclipses Roddick's overall game.
Some of you might've misinterpreted the quoted post because of how it was written. That or you're Federer fans who don't want to believe anything other than Federer is the best at everything.
And as I said, if you can prove me wrong, do it. It'll further everyone's knowledge on the subject.
- Epic logic/reasoning/deduction fail.
