Wonder why a small city like Tandil, Argentina (population 101, 010) has produced a few of the current top ballers in the world including U.S. Open champ Juan Martin del Potro? Juan Monaco isn't so sure about the answer either. My guess? Winning breeds winning.
Modern tennis isn't a hitting game - it's a running game. So check out this video featuring some footwork + balance training techniques you could do at home starring former baller Justin Gimelstob.
[Videos: ATP World Tour]