"You can't teach height". That's what Andy Roddick said last week after being dismissed in the third round by six-foot-nine John Isner and his frightening serves. Today, that notion was taken to a new level when six-foot-six inch Juan Martin Del Potro obliterated Rafael Nadal in the semifinals of the US Open. Never before has tennis witnessed such an all-court display of powerful yet graceful tennis from a man so large. It was truly an intimidating performance from a player who now is clearly close to achieving the massive potential so many have predicted for some time now.

Yes, Nadal is still suffering from a stubborn abdominal strain that rendered his serves nearly impotent and reduced his ability to move the Argentine around the court. But even if Nadal were 100% it would have been a difficult task for him - or anybody for that matter - to have defeated Del Potro on this sunny day. Nadal finally admitted after the match that his injuries were bothering him but true to form, he didn't offer it up as an excuse as he was obviously in awe of how dominating Del Potro was.

Rafa is the man who is usually running his opponent around the court, leaving them exhausted after one too many extended rallies. Not on this most welcome gorgeous late summer afternoon in Gotham. Nadal was the one who looked visibly helpless and irritable, even venting some frustration at the chair umpire, something one rarely witnesses from the polite Mallorcan.

Nadal also had a failure of strategy and tactics of sorts on Sunday. Knowing how vicious and deep Del Potro is capable of striking his groundstrokes, Nadal should have crept closer into the court on returns, especially during second serves, and rob Del Potro of a little time. Easier said than done obviously as when Del Potro is that consistent, it's hard to sustain an effective strategy.

Additionally, Nadal may have been wise to utilize the slice more frequently on Sunday. His usually tricky and high-bouncing topspin shots fall right into the hitting zone of Del Potro - unlike against Federer, where Nadal's shots zero in on the Fed's high backhand side - making it cannon fodder. Early in the match when it seemed Nadal may strike with an early break, Nadal was hitting low slices and nearly wrested control of the encounter. But again, with Del Potro forcing the issue and being the aggressor Rafa was not able to engage the tall man in longer rallies.

The good news for the Nadal camp and his many fans is that it was quite an accomplishment to even reach the semifinals, especially with only half a serve. There's no reason to believe that Rafa will not be one of the favorites when the Grand Slam season starts up again in January in Australia.

Del Potro, regardless of the outcome of his final Monday afternoon against Roger Federer, is ready to make a push for number one in the world over the next twelve months. After he had Federer on the brink of defeat in Paris, when he owned a two-sets-to-one lead over the eventual champion before nerves got the best of him, Del Potro has been on a mission to prove that he is ready to assume the role of Grand Slam champion.

Is there a chance that he'll take down The Roger on Monday? Well if he plays the way he did on Sunday then yes, of course. But he truly has to play that well. For one thing, he'll be on the receiving end of Federer's serve and not the spin deliveries that Nadal was forced to hit. Secondly, he hasn't proven to Federer in their previous meetings that he can beat him. In their six meetings, Del Potro has taken sets from Fed on only one occasion, in the previously referenced French Open semi. How much that weighs on the young man's mind will surely be a factor.

And if he is to challenge, let alone beat Federer, it is imperative that he secure the early lead. If not, game over. Novak Djokovic learned that lesson - again - on Sunday. Having just broken Federer and serving with a 4-2 lead in the first set, Djokovic lost his service game at love and the match was for all intents and purposes over at that point. The remainder of the semifinal was of relatively high quality but the script was eerily similar to their meeting in the 2007 Open final; Djokovic has break opportunities and leads in the first couple of sets and then Federer comes back to win in straight sets.

When playing Federer the first commandment is - thou shall not hit a ball to the Federer forehand. It still appears that Rafeal Nadal is the only one who has studied the Way to Beat Roger Federer textbook. Once again today Novak failed to keep the ball away from The Roger's strong side on the crucial points.

And of course Roger played like Roger usually does, with consistent strength off the grounds punctuated by wise and effective forays into the net and mid-court slices to entice his opponent into mistakes. And then there was that between-the-legs shot for a winner in the final game that seemed to signal, yes indeed the King's reign is far from over.

NOTES:
I wish Dick Enberg, who possesses a classic, smooth commentator's voice, would stop saying "Noduhl" instead of Nadal.
I'll say it again - why can't CBS show the match at night on Monday? Or at least start the match at 7? Showing it at 4 is an insult to fans and makes a mockery of their supposed complete and comprehensive coverage of the tournament. And if they don't want to go up against Monday Night Football, then have it stated ahead of time that they'll show the match on Tuesday night in case it's postponed from Sunday.