Grand Sam:
Sam Stosur's Serve
Tom Downs
Sam Stosur and I both grew up in the state of Queensland, Australia, in towns about 30 minutes apart. I was a couple of years ahead of Sam in the Australian juniors and first saw her play when she was 13 years old at a women's open tournament.
Even then she was heralded as one of Australia's great hopes. When I watched her play, I saw why.
I was immediately impressed with her fluid, natural service motion and her heavy penetrating forehand. I had never seen a girl that young with a kick serve that good--much better than most of the boys playing the same tournament.
The same could be said about her topspin forehand, which resembled that of a male tour player. At that young age, both strokes were technically very similar to the way she plays today.
Sam was a fan of men's tennis. From the beginning she wanted to play like a guy and trained with my junior male rivals in the Queensland area. But Sam also admired the way Steffi Graf played, dominating points with her forehand and using her slice backhand to set that up.
Developing that type of game style was common for many Australian girls of her era. They were taught to play like Aussie male players.
That meant playing all court tennis including serve and volley. This was coupled with varied, penetrating slice backhands, and a modern men's forehand. The approach worked for Sam, Alicia Molik, Rennae Stubbs, Rachel McQuillan, and Nicole Pratt, all of whom had successful pro careers.
The next time I saw Sam play was a few years later when she and I were both selected to represent Australia in a junior invitational event against Japan. Then, fast forward another 5 years to the Saddlebrook Resort in the Tampa, Florida area.
While I was coaching at Saddlebrook I was reintroduced to Sam by her coach at the time, Gigi Fernandez. Sam had come a long way from the Gold Coast juniors and had just won her first Grand Slam doubles title at the 2005 US Open.
For the rest of that year, I was Sam's hitting coach. Then, after she parted ways with Gigi in early 2006, I spent a great deal of time on court with her alone.
For a next year and half, I trained Sam between tournaments and also travelled with her to certain events. During that period she won another 3 Grand Slams doubles titles and was also ranked around the top 50 in singles.
She also had some big singles wins over players including Amelie Mauresmo and Lindsay Davenport. But her singles results lacked consistency.
One issue was that because she would go so far in doubles--usually making the finals--she would miss the qualifying event for the next week's singles event. Another factor was the time she was forced to take off the tour and the end of 2007 seasons to recover from Lyme disease.
That changed in 2009 when she reached the French Open final. Interestingly, Sam was probably the only Australian junior I knew who dreamed of winning in Paris instead of Wimbledon or the Australian.
Sam backed up that French final with her first Grand Slam singles title at the 2011 U.S. Open. She is now well established as one of the world's elite women's players in singles as well as doubles.
It was great to work so closely with Sam during that period at Saddlebrook. I've always been a student of the game, and our work gave me the opportunity to understand more about her two signature shots, and also, learn how they were developed.
Sam explained to me that Ian Brady, an Australian coach in Queensland, was a formative influence during her early years. Although he is not well known in the states, Ian has a reputation in Australian tennis as a pioneer in the areas of technique and biomechanics.
In this first article I want to take an in depth look at her serve, including the differences between her first and second deliveries. Then in the second article I'll take a look at her forehand, including the adjustments we made to make it more consistent.
Finally, we'll look a series of playing guidelines we developed. These guidelines helped Sam understand how to use the serve and the forehand together in a game style that took her to the top of women's tennis.
Serve
Sam's serve--particularly her second serve--is generally regarded as one of the best our sport has ever seen. She can hit it to a variety of locations with a variety of speed and spin combinations.
Both of Sam's deliveries are really versions of a kick serve. Similar to the great Pete Sampras, Sam hits both her first and second serve with significant topspin, far more than any other current women on tour.
Like Sampras the difference between the first and second serves is a matter of degree. She also will at times hit heavier first serves with less speed that are more like her first delivery. (For John Yandell's classic series on the Sampras Serve, Click Here.)
The high topspin element makes her serve very heavy, and she can kick the ball extremely high and wide in the ad court. But Sam can hit with more slice to get the ball wide in the deuce court and can also flatten it out when she desires.
Sam is one of the very few women's players whose serve biomechanics are similar to the men's. But I believe that developing a solid kick serve has little to do with the fact that the men are generally stronger.
The issues are getting the fundamentals and the basic synchronization of the motion right. I think that every player—male and female--can learn from Sam's motion to develop or improve their own kick serve.
Stance
Let's take a look at the basic motion starting with the stance. Sam stands with the front foot partially open to the baseline, but watch how it turns as the motion starts and becomes parallel or something close. The same can be said of her body, which starts somewhat open but immediately starts to turn.
Her weight starts forward, but quickly rocks back to load the back leg. Notice also that her back right foot will moves towards her left. Because the back foot slides, this is technically a pinpoint stance.
But look at where the foot stops moving and what then happens to her weight distribution. When she reaches her maximum knee bend her stance actually looks similar to Roger Federer.
The left foot is offset behind the front and the weight is equally distributed. Federer's stance is only slightly wider and his body turn only slightly greater away from the net.
Compare these positions to so many of the women's players, such as Venus Williams, who bring the back foot forward and actually around and to the right of the front.
The fact that Sam doesn't bring the back foot all the way up is what allows her to really drive upward with both legs. A lot of players who use a pinpoint shift almost all their weight onto the front leg and jump off that leg only.
Sam's stance is also critical to understanding what happens to her body in the upward swing. Notice that when her racket falls down along her right side, her torso is still virtually square to the baseline.
Again compare this to Venus. At a similar point in her motion Venus's torso is almost completely wide open. At contact it has actually rotated past parallel to the baseline.
In contrast, Sam's body at contact is still partially closed to the baseline—again simil.ar to as the top men servers like Roger. This is one of the big keys to the way she generates power and spin. (In the deuce court, like Federer, this rotation naturally goes somewhat further so she is closer to parallel to the net with her torso.)
Toss and Contact
Another key factor in Sam's kick delivery is her ball toss and contact point. Her tossing motion is perfect. Rather than throwing or tossing the ball, she releases it out of her hand.
But the key to understanding her toss is the placement. The ball travels on an arc out of her hand from her right to her left. This leftward arc is what allows her to generate so much topspin.
On her first serve, her contact is much further to the left than the other women--at about 11 o'clock. Note also how the racket tip is also tilted to the left with the contact clearly inside or to the left of the racket hand.
This is very different than most women players who toss the ball much more to the right and often make contact with the racket tip straight up and the ball directly above the hand.
On the second serve, the arc of the toss and the resulting contact are even more extreme. The contact is clearly further to the left, at more like 10 o'clock.
Sam also gets into a great trophy position. You can draw the line that coaches love to talk about from the top of the left hand all the way down to the right elbow. As you can see, in the trophy position, Stosur has her right leg and hip very well loaded, and this allows her to explode up and out into the ball.
Swing Path
From the racket drop or the slot, Sam's racquet travels in a true 7 to 11 o'clock swing pattern on her first serve, and more like 7 to 10 on the second.
Biomechanical studies have shown how the rotation of the upper arm segment is a major key to racket speed. This rotation, often referred to as “pronation” results in the racket face turning over radically in the upward swing and followthrough.
The arm rotation is as pronounced on Sam's serve as any player on tour. Watch how her upper arm rotates forward or internally as she moves to the contact.
As her elbow straightens, the upper arm, forearm and racket now rotate together out into the followthrough. This continues until the racket face is at an angle of 90 degrees to the court, and sometimes more.
Note also the angle of her arm and racket to the baseline. On the first serve, they appear to cross the baseline at an angle of around 45 degrees. On the second serve, the racket moves even further to the right, crossing the baseline at something more like 30 degrees.
Followthrough
This pronounced left to right motion is the key to understanding the shape of the followthrough. On the followthrough on the first serve, as her hand comes down it moves back from her right to here left until it is roughly in line with her mid torso.
But on the second serve, the racket hand often stays completely on her right side. It's important to understand that this is just the natural consequence of Sam's toss and swing pattern.
If you watch her arm you will see that it is very relaxed, a characteristic of all great servers. The followthrough happens without a conscious effort to guide the precise finishing position.
Like Sampras, Sam finishes so far to the right because of her ball toss position and swing path. The swing path causes the followthrough, not the other way around.
This is very important to understand in developing your own kick. Many players try to force the finish to the right side, and this can create muscle tension that impedes racket speed and increases the chance of injury.
During my time with Sam, I used a couple of basic drills to work on the kick serve, and I want to share the same drills with you as well.
In the first drill, I would ask Sam to stand out near the doubles alley in the ad court. I would then ask her hit to kick serves aiming as close to the net as possible and landing as short as possible on the other side. The goal is actually try trying to "kick" the ball into the side fence.
This drill really focuses on the kick swing pattern and generates acceleration. It also naturally teaches you to stay more sideways during contact.
A second drill, was to have Sam stand halfway between the baseline and fence and serve hard and deep into the box in the ad court. Again, the idea here is to work on acceleration and hitting "up and out on the ball,” creating the heavy spin necessary to bring the ball down in the shorter distance.
A third drill that she did was to move back and then turn to face the back fence standing about 5 feet in front of the fence. From there, she had to hit the ball so severely upward that it went over the fence. This is similar to the drill Chris Lewit talks about in his kick serve series. (Click Here.)
These drill will really help any player develop the feel for a heavy kick and are a good check as to whether the basic technique is correct.
So that's it for the serve analysis! Stay tuned next to learn about the forehand and playing guidelines.
