Juan Martin Del Potro's
Forehand

By John Yandell

Does Juan Martin Del Potro have the biggest forehand in tennis? You might conclude that, at least for the duration of the 2009 U.S. Open on a fast hard court. Although we don't have any measured spin data, the shot seems relatively flat and is definitely hit with supersonic pace. When you saw Del Potro set up on many balls during the Open, even in the final against the great Roger Federer, you could just feel that an untouchable winner was coming.

If we break the stroke down technically, we can see that it is a fascinating and in many ways unusual combination of the multiple technical elements we've been studying for the last few months in the new forehand articles in the Advanced Tennis section. (Click Here.) So that's what we'll do in this article. If you want to see additional footage of his forehand, including movies to click through frame by frame for yourself, check out the Interactive Forum (Click Here.)

Flavor of the Month

One of the common fallacies I have observed in studying professional technique over the last few years is what I call the "flavor of the month." If a certain player dominates the game for a year, or for an event, or even just wins a big match, there is a tendency to assume that whatever that player is doing is somehow "better," and that we should all immediately construct or reconstruct a given stroke to imitate him.

But if you watch pro tennis over a period of years, you see that much of this phenomenon is cyclical. One player dominates with a certain grip or backswing or followthrough, etc, but then another player takes over with a different technical combination--and then that all changes again as that player falls away and another player rises.

In my opinion when you look at professional strokes there is no way to completely separate the technical elements and evaluate them independently from the players who use them. Since you can't clone Rafael Nadal and teach him a different forehand, it's hard to say definitively whether another technical combination - slightly different or completely different - would be more or less effective.

This is why I don't think it is possible to conclude in an absolute sense that at the pro level, a certain technical style is "superior." Most likely it's the combination of ability and technique that leads to success. One of the things that probably makes great players great is their intuitive ability to figure out the right combination for themselves.

And that's probably true at all other levels as well. And to me this is really one of the great things about the game. There are always going to be choices and multiple combinations of elements in every stroke that every player must work through for himself or with a coach. This is an ongoing creative process that makes trying to understand, coach, and/or play great tennis endlessly fascinating.

When we look at Del Potro's forehand, it supports this conclusion. In many ways, it is similar to the majority of great forehands on the tour. And in other ways it's definitely different. Some analysts might not even consider some of the elements in his forehand "modern," except for the fact that he is using these elements to dominate most of the other players in the current game.

Grip

For years we've been hearing that the eastern grip is dead - that it should never be taught to elite juniors, that all the best forehands are "semi-western," whatever that means, that Pete Sampras and Tim Henman were dinosaurs, etc, etc. It's the same kind of thinking as the argument that claims the one-handed backhand is or should be extinct. (Click Here to hear what some of the world's top junior coaches are saying about that.)

	A classic eastern grip with the index knuckle and heel pad in line with the racket face.

Conservative grips are definitely relatively rare in the pro game, but then we look at the guy with a forehand as big or bigger than anyone - Juan Martin Del Potro - and see that he has a classic eastern grip. I think this is particularly Interesting because it's so different than the other Argentine players. Again, it points out the difficulty of making simple generalizations about grips, style of play, early training on which court surfaces, etc.

We've been over the grip terminology several times in previous articles (Click Here). According to the nomenclature we've developed, an eastern grip means that the base of the index knuckle and the center of the heel pad are both centered on the third bevel of the racket handle, counting from the top bevel and moving clockwise and downward from the top. In effect this grip aligns the palm of the hand with the racket face.

We've seen that, with the retirement of players such as Henman or Sampras, the only other top player with a similar grip is Roger Federer. For most of his career, Federer played with a grip shifted very slightly downward toward the semi-western. But, interestingly in the last year, he appears to have shifted back the other way more towards the classic eastern. (More on this in later articles.)

The basic characteristics of these conservative grips are a lower contact height, and a tendency for the player to position much closer to the baseline. With the high shot arcs and tremendous spin levels in the current game, this requires the ability to play the ball on the rise, something very few top players can do on a consistent basis.

We saw with Federer that typically his preferred contact height is somewhere between waist level and mid-chest. This means Federer uses more neutral stance than most players. But to maintain that contact height, Federer still needs to elevate off the court with one or both feet on many balls.

The same is true for Del Potro - most of his balls are played at waist level or slightly higher. And like Federer, he frequently steps into the shot when he is around or inside the baseline.

This is where his height at 6'6" comes into play. It's actually an advantage for this grip style in the modern game. That same strike zone for him - between the waist and the mid-chest--is actually a half foot or so higher than players like Federer who are around 6 feet or 6' 1". This is probably one of the reasons you see him hit so many neutral stance balls.

One additional interesting point is that Del Potro plays with virtually his entire hand on the grip. Much has been made of the fact that Federer and also Nadal both slip the heel of the hand off the bottom end of the handle, and how this was a key to the new more relaxed pro forehands. Again, we now have a top player with a huge forehand with a traditional hand alignment.

Backswing

If Del Potro's grip is unusual on the tour, his backswing may be unique. Many analysts have argued that closing the racket face radically to the court at the start and/or near the end of the backswing is critical to generating power. But Del Potro doesn't do this at any point. As with his grip, Del Potro's backswing defies "conventional" wisdom.

At the start of the motion, he raises the racket head and turns the face toward the opponent. It tilts slightly forward, but unlike players who truly turn the face completely downward, he takes the elbow and racket up together.

The racket moves upward on edge, and also moves slightly to the outside. At the top, the plane of the racket face stays virtually perpendicular to the court. This is the opposite of a player like Pete Sampras who raises his elbow much more in the early part of the backswing with the face of the racket parallel to the court.

The top of the backswing is high, probably as high as any pro player we have studied, with the racket hand above head level and the racket tip also pointing upward, beveled backward at about a 45 degree angle to the court. Compare this to a player like Federer where the racket head reaches only about shoulder level and the racket tip points slightly forward. (For more on the complexities of the backswing in pro tennis Click Here.)

The racket face also stays on edge as the backswing starts down. This is the other point where many top players turn the face partially or completely downward facing the court. Del Potro simply lets the racket fall without changing the angle. In the video it appears that this drop is coming from gravity with the arm quite relaxed.

At the bottom of the backswing, as Del Potro begins to set up the hitting arm position, the racket face can still be completely perpendicular to the court. Typically this is when the ball is in his strike zone or higher. When the ball is lower, the face will close slightly at the very bottom of the backswing, up to an angle of about 30 degrees. As we have seen, (Click Here) these angles at the bottom of the backswing are similar to players with similar grip styles such as Sampras or Federer.

Body Turn

His backswing may have different components, but one element in the preparation that Del Potro shares with other top players is the unit turn, and also the stretch of the left arm across the body. This appears to be one of the few widely shared commonalities on the forehand among top players. (Click Here.)

Watch how the motion begins with a sideways turn of the feet and torso. Although Del Potro has turned the face of racket toward the opponent, the racket is not moving backwards independently. Rather this is happening as a natural component of the unit turn - as the shoulders turn, the arms and racket naturally turn as well.

Compared to some other players Del Potro separates his opposite hand from the racket earlier - when the shoulders are turned about 45 degrees. But the key points are that the left arm continues to move to his right across the body and that the shoulders continue to turn.

This motion of the left arm continues until it is parallel to the baseline and pointing at the sideline at about a 90 degree angle. The video shows that from a front or rear view that the arm is also angled somewhat downward. This is similar to Sampras, or to James Blake, and different than Federer or Agassi who keep the arm parallel to the court surface.

This downward angle appears to be somewhat less common among the top players, most of whom have the angle of the arm more or less parallel to the court surface at this point in the motion. But I believe the important point is that the arm is pointing at a right angle to the sideline. This means the shoulders continue to turn, until they have turned a minimum of 90 degrees to the net, and usually somewhat further, something like 100 or 110 degrees.

The timing of this move is also critical. Del Potro begins the unit turn immediately as the other player strikes the ball. The full body turn and the left arm stretch are complete by the time the ball bounces on his side of the court.

Hitting Arm

In addition to a conservative grip, Del Potro's forehand shares another major and relatively rare technical element with Federer as well as with other players such as Nadal and Verdasco. This is his use of the straight elbow hitting structure on some forehands. In this configuration, the arm is straight from the shoulder to the wrist with the elbow fully extended. Like Federer, in most cases this means his wrist is also laid back at an angle of up to 90 degrees. This pushes the contact point further to the right and further in front of his body.

However, again like Federer, Del Potro mixes this straight elbow alignment with the more common double bend structure, with the elbow tucked in toward the waist and the wrist again laid back. As we have seen in our articles on the modern forehand in the Advanced Tennis section, with an eastern grip, this means elbow is usually less bent and spaced further from the torso than with the more extreme grips. (Click Here.)

The video shows that this distinction isn't black and white, and you can also find Del Potro somewhere in between the straight elbow and the double bend structure with his elbow just slightly flexed. We plan to do additional high speed filming that will help us understand under what conditions which players use which hitting arm structures, combined with what other technical elements. So stay tuned for that in the future.

Extension

A final, critical factor in Del Potro's forehand is the incredible extension of his swing forward and outward along the line of the shot. We know that the swing on the groundstrokes travels on an inside out arc from the players left to right until the contact. After contact, it curves back the other way as it moves into the followthrough. There is no such thing as hitting "through the ball" on a perfectly straight line. But with Del Potro, as with Federer and Verdasco, the arc of his swing is relatively flat and stays more closely aligned with the line of the shot for a greater duration.

We can see this by observing his extension. The "extension" of the shot is defined as the last point at which the racket is traveling outward and/or upward in the direction of the target, before starting the wrap either over the shoulder or across the torso, the final deceleration phase of the stroke.

Del Potro's extension when he is driving the ball in is strike zone is simply incredible. In part this probably stems from the length of his arms. But in any case, note the amazing spacing between his hand and the left side of his torso.

The wrist is at about eye level and the racket hand is roughly even with the left side. At this point the distance from his left shoulder to his racket hand is probably two feet or more, as great or greater than any player we have filmed. This is indicative of the relatively flat arc of his swing and probably accounts as much as anything for the supersonic pace of his forehand and his ability to generate effortless winners.

Windshield Wiper

We've seen how the windshield wiper action is related to the increased amounts of spin the modern game (Click Here) and, as with all the current top players, Del Potro uses the wiper to a greater or less extent on virtually every ball.

Sometimes he comes through with the racket only slightly turned, with the plane of the racket close to on edge at the moment of greatest extension. But more often, the racket tip has turned over up to 180 degrees by the time it reaches the extension point. As with other top players, you also see him use the wiper on lower shorter balls.

Although Del Potro's forehand appears relatively flat, we know that even players like Sampras and Agassi generated ball rotation that approached 2000rpm on average. Nadal on the other hand averages well over 3000rpm, with Federer somewhere in between. If we get the chance to film Del Potro for spin, it will be interesting to see where exactly he falls in this range.

Reverse

A final variation in Del Potro's forehand is his use of the reverse finish, a technical element first identified and conceptualized by the great Dutch coach Robert Lansdorp (Click Here). By reversing the finish, we mean the racket head finishes on the player's right side instead of crossing to the other side of the body.

Like other players, Del Potro uses the reverse when he forced for time on the run. He also uses it occasionally in the middle of the court when the ball is fast and gets a little past him. In the reverse, the spin comes from the rapid upward brush of the racket as opposed to the hand and arm rotation in the wiper. But Del Potro is so dominant off the ground, and his preparation is so consistent, that his use of the reverse is relatively rare.

Will Del Potro back up his Open win with more performances at the very top level? Or will he fall victim to the pressures of success like Novak Djokovic? Will he continue to dominate with his amazing forehand? Or will another player with a forehand with a different technical configuration become the newest biggest hitter? That's why they'll play the 2010 tour season. And stay tuned for the rest of his game in the Stroke Archive next month.