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Tóm tắt nội dung (trích từ tài liệu gốc): USPTA Player Development Program Anatomy of a modern shot � The hitting and recovery phases Modern tennis, like its conventional predecessor, has many commonalities that if properly recognized and understood, make teaching the modern game more profitable and enjoyable for teachers and players alike. continued next page Volume 3, No. 1 February 2006 First, it is important to differentiate between a "commonality" and simultaneously. The components without color have been covered a "specific difference" in playing styles among individuals. in the previous inserts. Out of necessity, we discussed f
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USPTA Player Development Program
Anatomy of a modern shot �
The hitting and recovery phases
Modern tennis, like its conventional predecessor, has many commonalities that
if properly recognized and understood, make teaching the modern game more
profitable and enjoyable for teachers and players alike.
continued next page
Volume 3, No. 1
February 2006
First, it is important to differentiate between a "commonality" and simultaneously. The components without color have been covered
a "specific difference" in playing styles among individuals. in the previous inserts. Out of necessity, we discussed footwork
as part of the hitting phase of a shot, but the graphic shows the
Commonalities are broadly accepted principles that apply to almost obvious with the yellow component disc � that footwork is an
every modern player. The best example may be the correct technique integral part of all three shot phases.
for hitting loaded, open-stance forehands and backhands and how a
player loads the outside leg, explodes into shots with kinetic energy Similarly, the kinetic chain (symbolized by a chain linking the
and lands on the most appropriate leg for maximum recovery. seven components) appears throughout the hitting phase and
into the first component of the recovery phase (seen below in
Specific differences are numerous among players and may include Exhibit I). The kinetic chain is the sequential coordination of body
a player's style or flair, which should be distinguished from his more segments (feet, legs, hips, trunk, shoulders, arm and wrist) to
general hitting process. For example, while Hewitt and Kuerten achieve more force than would be possible if the player omitted
have commonalities in their shot-making, they may differ in any of the segments.
minute specifics such as how they hold their grips or finish a shot
with a particular wrist wrap. Roddick's abbreviated serve can be This increased force is the advantage of angular momentum
considered as a specific difference from most other players. over linear momentum. We repeatedly use the term "load
� explode � and land" to explain the basic mechanics of modern
So, while there are numerous minute differences to players' styles groundstrokes as hit by experienced players. Loading the outside
that might be confusing at first glance, we can find and must study leg for a groundstroke provides the axis around which the core
primarily the many commonalities that are key to modern shots and and arm rotate, generating angular momentum (see Exhibit II).
are similar among all players and the way they strike the ball. When demonstrating this concept to less experienced players,
the teacher may more appropriately demonstrate a load � rotate
We will explain these keys to modern shots as we delve further � and weight transfer skill.
into the final seven components of the anatomy of a shot � starting
with No. 5, shot selection, in the hitting phase, and continues The process of loading, exploding and landing happens
through the recovery phase. throughout the hitting phase. Loading occurs during the
backswing; the explosion into the shot happens as the body
Hitting phase uncoils into the forward swing; and the landing is part of
Exhibit I below is the place to start. It illustrates many recovery. These concepts are explained in more detail in the
different processes that are happening both continuously and following explanation of shot anatomy.
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Exhibit II
Load Explode Land
Shot selection II. Types of shots:
Regardless of a players groundstroke capabilities, he or she still The type of shot selected will generally fall under three
has to know when and how to use them. As teachers and coaches categories:
it is important for us to provide a foundation for players to make A. Offensive � shots that are intended to put the shotmaker
good decisions. Shot selection involves spin, speed, direction, in an offensive position or in control of the point.
purpose, and is highly related to recovery. It is a process of
integrating technique with tactics based on circumstance or B. Neutralizing or rallying � shots that are intended to
strategic approach. sustain a rally and/or neutralize your opponent's shots
so that no one is controlling or dictating the point.
Like many of the other components in Anatomy of a modern shot C. Defensive � shots that are intended to defend against
(June 2005 ADDvantage), shot selection can be an extremely the opponent's offensive shots and hopefully allow the
detailed topic. This very general explanation will be explained player to reestablish neutralizing or offensive shots.
in greater detail in a later issue under tactics and strategies. At Strike-zone setup
that time, we will also be referencing many noted strategists Strike-zone setup requires applying efficient footwork to get to
and systems such as System 5 and The Strategy Zone by Nick the position judged best for performing the correct technique for
Bollettieri and Lance Luciani. the selected shot. However, it might be simplified by saying as
Choosing the right shot at the right time is key to not only technique improves, so does the ability to predict and move to
playing tennis well, but also winning. Remember, there is no the most effective strike zone.
such thing as a low percentage shot if it is executed in the Strike zone encompasses both the ball's distance from the body
proper situation. and its height. Most players have an optimum height where they
I. Determining factors in shot selection: will try to contact most groundstrokes. This is often referred to
There are many factors that determine the shot a player as the "wheelhouse." When the optimum can't be reached, there
should hit in a given situation. Usually, it is a combination of are variations above and below this zone. Upper-level and lower-
these factors and not just one factor that influences a player's level strike zones have to be addressed in the modern game. It
is no longer just a waist-high level for the optimum contact on
shot selection.
groundstrokes. For example, today's top players have a higher
A. Pace of the oncoming ball � a fast, hard-struck ball may optimum contact point on groundstrokes than players of the past.
limit a player's decision and movement time. These shots can be driven into the court, allowing a player to take
B. Depth of the oncoming ball � as with pace of the ball, control of the point. Or, when a player is in control of a point these
depth will also limit the shot options of a player.
shots hurt an opponent and force a weak response.
C. Spin � The amount or type of spin will affect the shot
selected. Strike-zone setup involves such preparatory skills as anticipation,
D. Height � where the ball is in relation to the net affects prediction, and interception. These skills can be learned and
improved with training.
shot selection.
E. Balance � the dynamic or static balance or inbalance of
the player. Anticipation:
F. Court positioning � where the player is going to be positioned In review (from Anatomy of a modern shot � Vol. 2, No. 3) there are
when executing the shot helps determine shot selection. two types of anticipation. Total anticipation is predicting what an
G. Court positioning of the opponent � will the opponent be opponent will do; partial anticipation is predicting what an opponent
in or out of position when the shot is played? will not do in a given situation.
H. Strengths/weaknesses � both the player's and opponent's
strengths and weaknesses must be considered. Partial anticipation is what most commonly happens on a tennis
I. Recovery position � the amount of court the player court, since players are rarely able to determine exactly what shot
will need to cover to be in proper position to play the an opponent will hit and exactly where the ball will go. It involves
cues that a player can use to more accurately predict what shot is
opponent's next shot.
J. Playing conditions � wind, sun, court surface, etc., all play not coming and therefore focus on what could be coming. These
cues can come from an opponent's:
a part in choosing what shot to hit.
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� Technique � cues in the grip, balance, swing path, body stance, Drill 2: Up and back drill
footwork (or lack thereof), ball toss, etc. Purpose:
� Court position A footwork drill to increase a player's ability to quickly move forward
and backward on the court while emphasizing proper loading, strike-zone
� Patterns, tendencies, strengths and weaknesses positioning, rotation and follow-through.
Prediction Description:
Predicting is the foundation skill in learning to play tennis and is
still crucial at its highest level. The ability to recognize the spin, 1. Player "X" starts at the baseline.
speed, height, trajectory and depth of an incoming ball is the basis
of establishing an efficient strike-zone setup. Players must predict 2. Pro tosses ball short to player.
not only where the ball will land on their side of the court, but they
must also predict (based on the spin, speed, etc.) where the ball will 3. Player moves in quickly, loads on dominant side leg, explodes through the
end up. We have often seen the inability of young players to predict shot, lands on non-dominant side foot, and completes shot with hips and
when they run toward a ball and then end up reaching high over their shoulders facing single sideline.
shoulders to try and hit it.
4. Pro tosses next ball deep, pushing player back to hit shot so that loaded
Professionals who teach by hitting from a basket to a stationary leg is back. Player must explode and still rotate prior to contact. Player
student find that before the lesson is over their student can hit continues rotation in the air and lands on left (or appropriate leg) with
a reasonably good groundstroke. However, once the "perfect hips and shoulders now facing opposite singles sideline.
feed" is not present the students newfound success may turn
to discouragement and lack of interest when they find they are 5. Pro continues to alternate a short toss and a deep toss to keep player
unprepared to predict accurately where the ball will land and, more moving up and back.
importantly, where the ball they are hoping to hit will end up.
Variations:
1. Can use either forehand or backhand groundstrokes.
2. Use targets for student to hit to.
This process of learning to predict should start at the beginning
of an instructional series and is easily practiced in a variety of
ways off the court.
Intercepting Backswing
Intercepting is the process of moving to a spot where you have Backswings come in a variety of styles, often varying from player
predicted the incoming ball will end up and ideally being there early to player and shot to shot.
enough to be waiting in a loaded strike-zone setup. Beginners
might be encouraged to wait in position before the ball lands on Take back styles
their side of the court. World Class Tennis Technique explains that there are two styles
of take backs on the forehand side: the single unit turn and the
Here are two drills from David T. Porter, Ed.D., which can help leading elbow turn.
players work on strike-zone setup:
However there are commonalities between all modern, topspin
Drill 1: Eight-ball footwork drill � Catching ball on hip groundstroke backswings: looping the backswing on the forehand
side and using the body to prepare the racquet for both forehand
Purpose: and backhand. The modern backswing, especially on the forehand
A footwork drill to increase a player's ability to change directions quickly. side, is almost exclusively done with a loop. The loop facilitates a
better transfer of momentum and helps players handle the varying
Description: heights of incoming balls. The second commonality is that the body
1. Player "X" starts at the center of the baseline. is used to prepare the racquet. The first move is always with the
2. Pro throws or feeds eight consecutive balls to various parts of the court foot, hip and shoulders and this helps keep the backswing from
getting too large or too far away from the body.
that are just barely within the reach of the player, providing he reacts
fast, runs fast and is quick to intercept the balls on the first bounce. The The decision, on which style of backswing a player will use, should
pro must be the judge of where and at what speed to throw the balls. be that of the player. The player will naturally gravitate towards a
3. It is important to feed the balls so that as soon as players catch them, he style that feels more natural and is more efficient for their game.
or she must immediately change directions to move to get the next ball. The style of take back might never be mentioned unless a pro
4. The pro should allow the player only a brief time to rest before repeating feels the student needs to be aware of the process to help their
the eight-ball drill again. performance. Using the hips and shoulders to take the racquet
5. The drill can be varied by adding a racquet for the player to run down the back is a something that could be taught early on in the process
shots and hit them back. to help the player create efficient and effective shots.
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The single unit turn is characterized by: The shape and height of the modern backswing should be
� Moving the racquet back in synchrony with the shoulder turn measured against the incoming shot. At the 2005 USPTA World
� This movement implies a rotation of the whole racquet arm Conference, the Player Development Advisory Council discussed
the backswing and the height of the take back. Everyone agreed
about the shoulder that the highest point of the loop should be above the level of
the incoming ball. This enables the player to have the appropriate
Leading with the elbow turn is characterized by: forward path, whether the ball's bounce is low, medium or high.
� Moving the elbow back in synchrony with the right shoulder
� Pointing the tip of the racquet to the oncoming ball Loading
� Closing the racquet face as the elbow is raised Discussing only the path of the backswing does not convey the
� Pivoting the forearm and the racquet about the elbow so importance of the backswing in generating force for modern
shots. During the backswing of a modern shot, there is much more
the racquet is rotated up to a position above the elbow and going on than just racquet preparation. This is the energy storing
shoulder phase of the shot, when loading or coiling takes place. Loading is
explained as the storing of energy in the large muscle groups. The
shoulders, torso, hips, legs are all loaded, storing up energy in the
backswing, to be released with the forward swing to contact.
Timing
The backswing should be made early enough so that the player
can make the best contact on the ensuing forward swing. There
are some variations in timing among players, primarily as a
matter of style. It's important to remember that the backswing
allows the player to be prepared to make optimum contact.
Single unit style Forward swing
In the forward swing component we see the forces that were
accumulated are uncoiled into the shot, generating the appropriate
technical response for the given tactical situation.
The kinetic chain is very much involved in the forward swing. It
is the differentiating factor between angular and linear strokes,
or modern and traditional shot making. This is the "explode" part
of the modern load-explode-land hitting style. The path of the
forward swing also directs the amount or degree of spin imparted
on the ball.
The racquet path will depend on the shot selected and the strike
zone. Topspin shots can be hit with a low-to-high path from lower-
and medium-level strike zones. Upper-level shots inside the court
( Zone 3 for example) will not use the low-to-high path, but take a
more level or even downward path on the ball with the angle of the
Elbow leading style racquet face and the speed of the swing imparting the topspin rather
than the low-to-high brushing motion of the lower-level shot.
The single unit take back is used by players who have a more
compact swing, such as Andre Agassi and Martina Hingis, who Contact point
have a reduced swinging radius and rely more on the development The contact point probably is the most critical factor in every
of angular momentum during their rotations toward the ball. stroke as the alignment of the racquet and the ball determine a
shot's direction. With the variety of grips that can be used to strike
Players with the elbow leading style include Lindsay Davenport the modern forehand, the contact point in relation to the body will
and Roger Federer. These players have better timing skills and can be different depending on whether an eastern, semiwestern or
use the elbow leading take back to their advantage, optimizing western grip is used. However, even with these differences there
racquet head speed without hitting the ball late. still are some commonalities in modern shot contact point that
should be identified:
Loops
While use of a loop backswing is almost universal on modern � Hips and shoulders are parallel to the net (or perpendicular
groundstrokes, players differ in the size of the loop � some use a to the target area) at impact during the loaded open-stance
larger loop and some use a smaller loop. Some players use circular forehand.
loops, while others use a more elliptical loop. The loop provides a � Ball contact is in front of the body.
more fluid stroke and allows the racquet head to accelerate over
a longer distance. Even though a player may exhibit a large loop � On forehands, the free hand plays a key role in balancing
body weight for contact.
on most shots, you will see smaller loops on the return of serve �
Racquet head acceleration culminates in maximum speed at
and shots with little or no preparation time. contact.
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Recovery phase of finishes, the arm decelerates and rotates as it comes across
The recovery phase of a shot has two components � follow-through the body along with angular rotation of the shoulders and
and recovery (see Exhibit III below). trunk. Generally, the player wants to have the elbow high in the
deceleration phase. In the vertical finish, the arm is raised above
Follow-through the head vertically to the court as the racquet decelerates.
The follow-through is an extremely significant element of the
modern shot that provides: Careful study of the follow-through leads to the conclusion that
there are four places where a player's racquet might finish in
� The completion of the rotation required for maximizing relation to his body: vertical (over the hitting shoulder), elevated
angular momentum. This full rotation also plays a key role (over the opposite shoulder), horizontal (chest high/across the
in body positioning for maximum recovery efficiency. By opposite arm) and inverted (across the opposite hip/thigh).
following through in the direction of the target the dominant
side shoulder and hip continue to rotate and are pulled This is a tricky subject to discuss, because as teachers we often
to their final position, taking full advantage of angular look at the finish, or location of the follow-through, as an indication
momentum. of the racquet path. However, for the sake of simplicity in this
discussion, the terms only describe the location of the finish
� A path for the racquet to follow. This helps a player maintain without regard to the racquet path. For example, when a player
balance throughout the shot. strikes the ball at his ideal contact point, say about waist high, and
follows through over his opposite shoulder, his finish is elevated
� Appropriate acceleration through impact. This is particularly in relation to the racquet path and his body. If that player takes
important for imparting all types of spin and controlling a shot. a ball at shoulder level and finishes over the opposite shoulder,
If the follow-through is shortened, the racquet will have to the finish is horizontal in relation to the swing path, but we still
slow down before contact. consider it an elevated finish since the racquet finished over the
opposite shoulder.
� Normal racquet head deceleration. This can help reduce arm-
related injuries. Examining each possible racquet path and its finish would require
consideration of sport science, players' individual artistry and,
� A way for professionals to judge the quality of the stroke. frankly, some conjecture. So, as you think about the terms below,
please remember that they refer only to the location of a racquet's
After contact the racquet and arm continue forward until the shot finish without regard to racquet path.
played determines the direction of the finish. On the majority
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The follow-through finishes can be categorized into four types:
1. Vertical � finishing on the same side of the body, 2. Elevated � finishing over the opposite shoulder
straight up and over the hitting shoulder
The elevated finish is the most common finish. It is typically
The vertical finish is typically used on: used on:
� Shots when the player is unable to rotate the hips and legs � Drives where the ball is in an ideal strike zone
� Neutral or offensive shots off low balls. The player may � Drives when the ball is peaking or on the rise
impart both sidespin and/or topspin.
3. Horizontal � chest high, finishing around the opposite arm 4. Inverted � finishing around the opposite hip/thigh
The inverted finish is typically used on:
The horizontal finish is typically used on: � Excessive spin or sharp-angled shots
� Drives hit off high balls
� Drives that require additional topspin
In addition to the biomechanical considerations that make the Some of you, and even some of the members of the USPTA
follow-through an important part of the shot, it allows for variety Player Development Advisory Council, may question why it is
in shot production. necessary to go into such detail. The answer is very simple. We
are not writing a manual for players to digest word for word, but
Recovery we are writing a manual for tennis-teaching technicians who must,
The recovery portion of this phase may be examined both at a glance, be able to make the correct diagnosis and provide
physically and tactically. Physically, we look at how a player lands a cure for an ailment in a student's game. Without knowing the
and then moves to the ideal recovery area on the court. Tactically, minute details of how and why shot components are structured,
we look at where a player may choose to recover on the court a teaching professional cannot possibly give an efficient lesson,
based on tactical fundamentals. or offer a diagnosis and cure. Only by having an extensive
knowledge of teaching systems can USPTA Professionals provide
The physical technique of modern shot recovery starts with loading expert instruction and advice and gain the respect of both their
from a balanced strike-zone setup and then transferring weight as students and the general public.
part of an explosive (not necessarily power producing) rotation. If
the strike-zone setup is balanced and the weight transfer moves As we move forward, it is becoming apparent that the USPTA
a player either forward or toward the middle of the court then Player Development Program inserts will continue for as long as
recovery is both economical and efficient. However, if the strike- continuing education is paramount to the Association's purpose.
zone setup requires a step back or away from the middle of the
court then additional time and steps must be taken to achieve the Credits and thanks
appropriate recovery position (see Footwork in modern tennis Once again, we must thank our extraordinary resources whose
� Vol. 2, No. 4). advice and works have aided USPTA in this chapter:
Tactically, the direction and type of shot hit will determine the area � USPTA's Player Development Advisory Council: Nick
to which a player will recover on the court. The general rule of Bollettieri, Jack Groppel, Ph.D., Jim Loehr, Ed.D., Rick Macci,
recovery positioning is that a player should recover to the middle Paul Roetert, Ph.D., Eliot Teltscher, David T. Porter, Ed.D., and
of an opponent's angles of reply. Tim Heckler, USPTA CEO
Player 2 Player 2 � World-Class Tennis Technique, Paul Roetert, Ph.D., and Jack
Groppel, Ph.D., editors
� USA Tennis High Performance Coaching Program manual
� David T. Porter, USPTA Education Committee Chairman and
professor at Brigham Young University � Hawaii
� Bret Hobden, USPTA presenter on modern tennis techniques
� John Yandell and Advanced Tennis Research's high-speed
video of world-class players
� "The Strategy Zone" by Nick Bollettieri and Lance Luciani.
X X
Player 1 Player 1
In this graphic, Player 1 has In this graphic, Player 1 has hit
hit a crosscourt groundstroke. a groundstroke down the line.
The graphic shows the possible The graphic shows the possible
angles for Player 2's best shots, angles for Player 2 to hit to
and the spot to which Player 1 and the spot to which Player 1
should recover. should recover.
Conclusion
This concludes the skeletal structure of Anatomy of a modern
shot. This topic was started three inserts (counting this one) and
24 pages ago. We initially thought the job of describing a shot
might be only a little more detailed than writing down the names
of the 11 components: foreperiod, reaction time, movement time,
footwork, shot selection, strike zone setup, backswing, forward
swing, contact point, follow-through and recovery. If you have been
one of the followers of our player development documents, you
probably understand just how complex it can be to try to explain
the "why" and "how" of each shot component.
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