Rafael Nadal has one of the best forehands in tennis history. He uses the same principles that several other top players in the world use and yet, his forehand looks markedly different. Few players in men's tennis combine the velocity and topspin generated by Nadal's forehand.
The forehand set-up
The Spaniard often uses his serve to force his opponents wide, leaving them with few options but to return the ball to his forehand, immediately giving him full control over the point.
In situations when an opponent's shot is heading towards Nadal's backhand, he usually runs around it and turns it into a forehand. These run-around forehands allow him to disguise his intended shot until very late in his swing, and hit an inside-in forehand down the line or an inside-out forehand crosscourt.
An eye for angles
Nadal's forehand starts like most top forehands, with the feet, torso, and racket turning sideways until they are at 45 degrees towards the net. As his backswing begins, his right hand comes off the racket and points towards the sideline, coiling his torso past 90 degrees.
However, in a move different from other players, he straightens his hitting arm at the bottom of the backswing and keeps it straight through impact. This allows him to extend his racket towards the target even during an upward spin generating swing.
How does Nadal generate topspin?
At contact, he has more hand and wrist rotation, and this creates tremendous topspin. The primary reason why he hits with more spin on average than players such as Roger Federer, Novak Djokovic, Andy Murray, and Stanislas Wawrinka is that he swings upwards more.
He is famous for his reverse finish - his arm ends up very high behind his head, thereby increasing the upward angle and generating more topspin.
Nadal also has two basic finishes to his forehand - the across-the-body at shoulder-height version which he uses to combat higher balls, and his signature around-the-head version on lower balls and those hit on the run.
As a left-hander, Nadal has the advantage of hitting his forehand crosscourt to his opponent's backhand. Even for players with strong backhands such as Federer and Wawrinka, it becomes difficult to return when the ball is up high, and they end up sending back short balls that Nadal can attack.
Rafa is not the only left-hander to use this strategy, but he is arguably the best at it. Djokovic and Federer too have a lot of racket head speed on the forehand but don't make use of the reverse finish very much, because a ball hit crosscourt would go to their opponents' forehands.
The Spaniard has built his game around this strategy, but it must be noted that Federer has now figured out the chinks in it.
A combination of elements
It is this rare blend of great technique, racket head speed, and left-handedness that makes it so effective for Nadal to use the reverse finish in generating topspin. He has baffled many a top player with his punishing forehands, doubtless one of the most powerful weapons in his arsenal.