#2 More dominant on favoured surface
It is common knowledge that while Nadal loves clay, Federer's preferred surface is grass. Both have absolutely dominated their favorite surfaces, but the question remains as to who has been better on his favored surface - while also not being worse than the other on his least-favorite surface.
Federer has played 188 matches on grass out of which he has won 164, which means he has a win percentage of 87.2. Nadal on the other hand has played 424 matches on clay, winning a staggering 389 out of them - taking his win percentage to almost 92.
At the other end of the spectrum, Federer's win percentage on clay is 76 as compared to Nadal's 77. Nadal has been able to beat Federer at Wimbledon in 2008, whereas the Swiss has never beaten Nadal at the French Open in give attempts attempts. Overall, the two have played 15 times on clay and Federer has been able to triumph only twice.
Federer's win percentage of 89 at Wimbledon pales in comparison to Nadal's 97.5% at the French. Rafa has won Wimbledon twice and has a win percentage of 81 there, whereas Federer has won the French only once and his win percentage there is 80.
Who Are Roger Federer's Kids? Know All About Federer's Twins