Abstract:
A method of teaching and illustrating tennis strokes is described. The method consists of teaching and illustrating tennis strokes by dividing each stroke into five specially chosen stroke components, four of which cannot be seen without slow motion photography, and developing each component individually until the student is able to execute the full stroke. Typically, the components are taught in reverse order of their execution. The five stroke components are 1) the take-back, 2) the contraction; 3) the rotation; 4) the acceleration and 5) the strike. The instructor begins by observing the student&#39;s attempts to hit a tennis ball determine which components are missing. Once missing or deficient components are identified, the instructor and student can narrow their focus to just the missing component(s) without regard to constructing a entire tennis stroke.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority from Provisional Application Ser. No. 60/394,391 filed Jul. 8, 2002. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to a system for developing the strokes of tennis, that is, teaching the essential strokes, by decomposing each stroke into action components and facilitating the rapid integration of the components by developing them in the reverse order of their execution.  
       BACKGROUND OF THE INVENTION  
       [0003]     Traditional tennis teaching techniques use rote instruction methods combined with metaphors, templates, and rules to develop tennis strokes.  
         [0004]     The most common method for teaching tennis strokes, as recommended by the United States Professional Tennis Association (USPTA), the United States Tennis Association (USTA), and the United States Professional Tennis Registry (USPTR) relies on instruction by the use of metaphors, stroke templates, and rules (hereafter referred to as the MTR method).  
         [0005]     Examples of tennis teaching metaphors are: “hit through the ball”; “keep your eye on the ball”; “hold the ball on the racquet”; “take the ball early”. Examples of tennis explanation metaphors are: “She has talent”; “He choked”. An example of a stroke template is the following four steps: First, take the racquet back; second, turn and step forward; third, swing; fourth, check feet, balance, and racquet position. It is essential in the MTR method that the stroke template be learned as a single integrated unit. Examples of rules are: “keep your feet moving”, “bend your knees”, “hit the ball out front”, and “don&#39;t use the wrist”.  
         [0006]     Other, less common methods involve illustration by experts. These are also template-based methods in that the visual record of the expert stroke is a stroke template. Such processes are taught by well-known tennis instructors such as Nick Bollettieri, Dennis van der Meer, and Vic Braden. Lesser known names are Oscar Werner, John Yandell, and well as many others. While there are differences in approach, all have one aspect in common: Template based instruction.  
         [0007]     Although such processes are capable of teaching tennis strokes, these methods are limited by the extensive amounts of time and money needed to learn strokes and are further limited in that the strokes learned have a narrow application. Further deficiencies in the usual methods of tennis instruction are noted below,  
         [0008]     According to the present invention, which provides an entirely new method, one is able to teach tennis strokes in a remarkably short period of time, produce more versatile strokes, drastically reduce the cost of learning tennis strokes, and enable the student to engage in very productive independent study.  
       SUMMARY OF THE INVENTION  
       [0009]     Previous methods of tennis training have failed to recognize the importance of the development of mesoscopic neural components, that is, components of intermediate scale, between microscopic neuronal memory and macroscale template memory. See Walter J. Freeman III, Ph.D., MD. “Neurodynamics: An Exploration of Mesoscopic Brain Dynamics” Springer (2000); “Mesoscopic neurodynamics: From neuron to brain”,  Journal of Physiology  (Paris) 94: 303-322 (2000)) This work shows that one learns to perform a given action, such as a tennis stroke, by assembly of components, rather thasn by learning the action as a whole. Prior tennis instructional techniques fail to recognize this key aspect of the human learning process. Furthermore, such methods have failed to recognize and account for numerous other factors of human learning now known due to recent research by Professor Ellen Langer, Professor Walter Freeman and numerous other psychologists and neuroscientists.  
         [0010]     Examples of problems not adequately addressed by the prior art (which will be referred to as the metaphor, template, rule (MTR) method) are:  
         [0011]     1) Problems resulting from limitations of visual processing. The use of metaphor in place of facts has likely evolved in tennis due to the limitation of the human visual process in resolving the detailed action of a stroke. We call this the problem of observability. The observability problem has likely shaped much of what is taught in the MTR method today.  
         [0012]     Classically there are two observables: 1) The preparation, where the racquet is taken back, and 2) the follow-through after the ball has been struck. The details of the swing, especially the interval shortly before and at the time of ball contact, are unobservable to the human eye. While the advent of 500-frame/sec video has made the swing observable, it has not resolved the problem of explaining the details due to the fact that there is too much information to easily discern the critical components of the swing. Even the advent of affordable computer video editing systems provides too much data for rapid analysis. The result is that it is very difficult to differentiate between what is essential and what is coincidental in the details of a stroke. Thus, we find that the vast majority of teaching pros still rely on the use of metaphors in spite of the presence of large quantities of empirical data.  
         [0013]     The situation is further exacerbated by the tenacity with which the tennis community holds on to the metaphors of the past. For example, a wide spread belief is that a player can “hold the ball on their racquet” when in fact scientific studies show that the maximum time that a ball stays on a racquet is about 7 milliseconds or 7/1000 sec. This is far shorter than the round trip detection speed of the human brain, making it impossible to have any ability to “hold” the ball on the racquet. Another example of wide-held but erroneous belief is the notion that jumping provides a significant source of the ball velocity in a serve. Empirical studies show that at best this can provide  7 mph if the ball is struck at the moment of the jump. Another example is the belief that a player can “carve under the ball” to produce special dynamics at will. However, the relative slowness of human reaction time proves that this is clearly false. What may explain the retention of these false beliefs is that players, instructors, and commentators are reporting the sensations they receive from the sensory cortex a fraction of a second later than the actual action to which they refer. This sensory delay leads to wide spread beliefs that are not based in empirical facts.  
         [0014]     2) Problems resulting from the ambiguity of human language. The objective of language, in the role of providing directions to achieve a result, is to reduce the possible set of actions a person could otherwise consider to achieve the result to a unique set. Thus, it is nearly impossible for one person to tell another how to carry out a high precision physical or mental action in the absence of a rigorous formal language such is found in the physical sciences, except by chance. What can be done is to provide a series of approximating suggestions and directions that, over time, assists the student in reducing the trial and error process undergone in trying to converge to an action. In lieu of a precise formal language, traditional tennis instruction has accordingly become dependent on imprecise metaphors, templates and rules to provide the approximating directions.  
         [0015]     The speed of convergence of this series of successive approximations to a “correct” stroke is dependent on:  
         [0016]     the time devoted to trial and error activities (practice),  
         [0017]     the time devoted to studying and reflecting on the experience gained from the trial and error activities and from the directions of the instructor, and  
         [0018]     the number of trials needed to discover the right set of components,  
         [0019]     Of these, the number of trials needed to explore the space of all possible strokes is perhaps the greatest obstacle.  
         [0020]     To give a precise example to illustrate the difference in time consumption between a template based approach and component based approach we take a closer look at the interrelationship between instruction and practice.  
         [0021]     There exists a profound misconception about the nature of practice and how the quality of instruction reduces practice time. First, no one can tell a student exactly how to best hit a tennis ball. This is scientifically impossible due to numerous factors, one being the imprecision in our own preconception of the motor control feedback loops in our own brains. While science still has an incomplete knowledge of every detail of these loops, the average human has no conception of how these loops work. What we do know is that when an instructor tells a student how to hit a tennis ball, the entire body of information provided by the pro is fraught with imprecision. Quite apart from the imprecision of the language, there are too many variables involved that we do not understand combined with the fact that our brains do not make records of physical actions for any pro to ever be able to tell a student exactly how to hit a tennis ball. Further, even if it were possible to provide the exact method in words or illustrations, it is not possible for a student (except by chance) to produce a stroke based on a visual or verbal specification.  
         [0022]     Failure of the lay individual to understand this has led to the conception that when a student engages in practice, he (including “she” throughout) is repeating the pro&#39;s instructions. This is scientific nonsense because this is not possible. What is occurring is that the student garners some faint idea of what the stroke might be and then (in essence) performs an experiment to see if he is right. The only measurement the student has to determine if he is right is how well the ball is struck. There is an implicit assumption that the better the ball springs off the racquet, the more closely the student has reproduced the pro&#39;s instructions. But even this is inaccurate since most people who become professional players have better strokes than any of their teachers, so they simply are not reproducing what the pro instructed, or they would never get better than their teacher.  
         [0023]     This state of affairs is explained by the fact that practice is not rote repetition (which is virtually impossible). Practice is an process of experimentation directed toward discovering what is best. The instructions of the pro can only reduce the time of this experimentation process for the student by providing high quality information. The better the information the shorter the experimentation process. However, the instructor can do nothing to remove the student&#39;s need to experiment. Try as they may, no amount of instruction can stop this process. In fact, even if the student by chance executed the prefect stroke on the first trial, he would not likely be able to reproduce it a second time because there is no reliable memory record of the prior stroke.  
         [0024]     How our brains finally converge on a “correct” stroke by performing a series of experiments and computing differences between that experiment and previous attempts is still not fully understood. What is known is that we do not construct templates, but rather construct components that are retained without conscious memory. In the end, natural practice is experimentation not rote repetition. In the event an instructor were to stand right by a student and try to sincerely eliminate this experimentation process by forcing rote repetition, the student&#39;s learning process would be retarded rather than accelerated as confirmed by the work of Langer and others cited elsewhere in this application. Hence, when an instructor directs a student in producing a tennis stroke, it is an imprecise act. Its precision depends on the quality of the information the instructor has. It is well known that some are better than others. But no matter how good the information, the student must engage in experimentation to discover how to hit the stroke using their mind and body, not their instructor&#39;s.  
         [0025]     Further, no matter how hard an instructor tries, they cannot stop the natural dynamical processes of the student&#39;s brain. At best, they can only suggest an “approximation” to a stroke and then stand aside while the student goes through the process of experimentation to find the correct stroke. This experimentation process is akin to a random search in that the student must constantly try different variations on what they thought the instructor said to see if it works. Even when they do perform the “right” series of actions, their brains only records small components of the series of actions and so they must discover it again because there is no exact record of the full stroke. But because one small component was formed in their brains, their future searches are thereby reduced (so long as this component is retained, for which there is no guarantee).  
         [0026]     The situation described above is serious enough that one must address the role of exploration in forming any teaching regime. However, the situation is even more complex. Even when the student finds and retains what seems the perfect stroke, their brains will continue the exploration process since there is no universal measure of what is perfect. Even the top professionals continue the search for an even better stroke no matter how good their strokes may be. Exploration is an unrelenting drive of the human brain and nothing is ever accepted as perfect. In conclusion, the quality of the approximations provided in an instructional regime have a far reaching impact on the time the student must explore alternatives (practice) to find what is right. While no reasonable pro would ever encourage a student to explore all variations on their instruction, they are powerless to stop this natural and necessary process. While it is clear to all that the quality of information is important in reducing the student&#39;s experimentation process, what is not generally understood is that the order in which information is presented is just as important as the quality of that information in reducing exploration time. Since the instructor is powerless to eliminate the student&#39;s need to experiment, the question arises as to what should be the order that information is presented to minimize experimentation time.  
         [0027]     In order to convey some level of the importance of the order of presentation, we provide the following analysis. Let us suppose that we have two instructors A and B and that A will use the template-based approach, and B will use the component-based approach according to the invention. Now suppose that a stroke is known to have N stages and that each stage can be performed in k ways. Further suppose that each instructor can tell a student what the N stages to a stroke are, and that there are k modes in which a stage can be executed. Let us make a generous assumption that each instructor (assumed to be equally qualified) is therefore able to reduce the student&#39;s experimentation time through their coaching by 50 percent by eliminating half of the stages based on their teaching experience. Recall from our preceding discussion, that no matter how sincere the effort, the instructor cannot eliminate experimentation and may even stand helplessly aside as the student tries experiments that are clearly hopeless (because this is a natural and unpreventable process). As a result of this natural process, it is essential that the instructor find ways to reduce the total number of possible experiments. This is because the student will try many of these possibilities regardless of the instructor&#39;s wishes, and the number of possibilities he explores is proportional to the number that is available.  
         [0028]     The template-based approach of instructor A will create the potential for the student to explore N raised to the k power divided by two cases to discover the right stroke, after perfect coaching. In contrast, the component-based approach of instructor B will only create the opportunity for the student explore k times N divided by two cases. For the simple case where N=5 and k=10, the template-based approach of instructor A will present the student with some 48,828,125 cases to explore even after he has made his best efforts to simplify the student&#39;s task. In contrast, the component-based approach of instructor B will present the student with 25 cases to explore. Practicing 40 hours per week using the template-based approach of instructor A, the student will likely learn the stroke in about seven months, in the worst case, and in three months on the average. Using the component-based approach of instructor B, the student will learn the stroke in about one hour even if their personality is such that they inclined to explore all possibilities. This explains why most people have no hope of learning professional level strokes in their lifetime, no matter how hard they try. Hence, the order of presentation is significant! What is needed is a method of reducing the total number of possibilities in the search space (after coaching) to a figure that significantly increases the probability that the student will find an acceptable stroke within a practical time frame.  
         [0029]     3) The problem of associative learning. Humans learn most quickly through relevance. If an action has a result that can be associated to a value, it is learned more quickly than a meaningless action. It is very difficult to associate the abstract idea of a template with a result. This is because the vast majority of trials searching for the right stroke by following a template do not result in a successful contact between the ball and racquet. (We consider a successful contact between the ball and racquet to be one that produces a pleasing sound, look and feel and whose trajectory falls within the limits of the rules of tennis). In other words, when using templates, a successful result cannot be automatically associated to a value except by chance. Professor Ellen Langer describes experiments that confirm that rote learning such as template-based training are inferior to relevance based learning, see  The Power of Mindful Learning,  Chapter 4, the Hazards of Rote Learning.  
         [0030]     4) The Problem of Reflexive Memory. The human brain has very little ability to recall a reflexive action on demand, making it almost impossible for an expert to tell a student what she or he does to hit a tennis ball. The consequence of this is that no matter how good a player is, they have little ability to communicate their technique to a student. As a result, it is quite common to see a player telling a student what they do first or last to execute a particular stroke, omitting entirely what they do at the point where the racquet strikes the ball (Not only is the stroke unobservable by the student, it is effectively unobservable to the expert). This is because the first or last thing one does to execute a stroke is generally the only thing recorded by one&#39;s memory. Hence, the very nature of reflexive memory is an obstacle to teaching.  
         [0031]     This situation is further exacerbated by the fact that humans firmly believe that they can recall, on demand, the details of a reflexive action. Consequently, the experts firmly believe that they are imparting useful knowledge to the student and generally have no idea of the scientific reason that they are not. Occasionally, when student and teacher are “well matched” the student catches on, not because the teacher has done a good job of conveying the stroke, but because the student has a predisposition to do things similarly to the teacher.  
         [0032]     5) The Problem of Accurate Recall. The human brain has surprisingly very poor powers of recall (we reference the notorious lack of credibility of eye witnesses). Hence it is very difficult to repeat a newly learned action based on memory alone, or to recall, without an aid, what a teacher has demonstrated. The disparity between what one thinks was said or done during a lesson and the facts of what was actually said is so great that the best one can hope for with the MTR method is a very vague notion about a stroke to be conveyed.  
         [0033]     6) The Problem of Intentional Action. Accurately carrying out an intended action requiring precision is inherently difficult. Even if one had prefect recall, and the teacher conveyed their actions perfectly, a human&#39;s ability to carry out this action intentionally as prescribed is quite limited. Of particular significance is the fact that humans do not have a visual feedback loop to use to correct an action while it is being carried out. Hence they must rely on developing an internal somatosensory memory to tell when an action is incorrect. Even if the somatosensory feedback were to be developed to a perfect level, the speed of action on a tennis court so far exceeds the speed of the fastest somatosensory feedback loop in the human brain that the information would arrive too late to be useful. The MTR method, due to its preponderance of ambiguities, makes developing this sense almost impossible except by chance.  
         [0034]     7) The problem of disassembly and encroachment. The human brain may disassemble, over night, the knowledge of an action learned the previous day. Further, neurons devoted to one task may encroach and co-opt neurons developed for an infrequently executed task. In the MTR method, this leads to the curious situation whereby a student learns how to hit a serve or forehand really well and over night completely forgets how it was done. Any attempt at reproducing the stroke from any memory fragments that remain, or imagining how it was done, and acting intentionally to reproduce it, is usually futile. This is because the MTR method provides only templates, rules and metaphors to work from, and the ambiguities and imprecision of these elements make them nearly worthless in the absence of an instructor. Hence, the student is often paralyzed and discouraged by these events. (It is important to note that when people engage in what appears to be repetition to groove a stroke, what they are actually doing is experimenting to discover more efficient stroke components. Components are retained, whereas templates are discarded. What this means is that our brains over night discard templates used the previous day in order to be able to adapt to any new demands that may arise the next day. This process is a significant factor in adaptation).  
         [0035]     An instructive comparison can be drawn between traditional instructional methods and learning processes carried out essentially without instruction. In early childhood development, there are no templates, metaphors or rules to guide the development of physical skills. A child learns by exploration and experimentation. In this process of trial and error, the child develops many action components which do not constitute a purposeful act, but which become useful later when their environment begins to enlarge and change. This might be described as “component based” learning. It is the natural learning process and ensures the ability to adapt to new environments and circumstances not before seen. If templates were imposed on a child during the early developmental years, the results would be disastrous. In this context, the expression “you have to learn to walk before you can learn to run” has great validity; walking includes many components of running. Likewise, it is difficult if not impossible to teach a tennis stroke without first communicating its fundamental elements, that is, the Active Cmponents identified and emphasized according to the method of the invention.  
         [0036]     Similarly, the natural learning process is a series of successive approximations. At each encounter with a new environment, the individual acquires data and formulates approximate responses based on previously developed components. After these responses are formed and compared to the stimuli, new components may be called for. These new components can only be formed after the process of a first approximation and comparison has been completed. In short, if a first approximation is not formed or is restricted by inhibitions, the second approximation cannot be even conceived, thus adaptation stops. The first approximation may be thought of as a neural layer or foundation on which a more advanced approximation is formed. Once this new layer is in place, the individual may envision new responses to the environment that were not previously possible.  
         [0037]     If a very complex template is imposed on the individual rather than allowing this first approximation to form in its own time, e.g., if one tries to teach a complex motion such as the tennis strokes without adequate grounding, subsequent improvements may become impossible, and the result can be disorder. Neurons put in place in response to template training are unstable in that they can be easily disassembled or encroached upon by more stable configuration. Neurons, while seemingly numerous, are used sparingly in the brain&#39;s self-organization process. If one use is not well founded, the neurons can be reallocated to other tasks. This encroachment process can be often seen when an individual loses their hands and become efficient at using their feet. This process suggests that the Hebbean model (see Kandel, Schwartz, and Jessel,  Principles of Neural Science,  Elsevier Press, NY., p. 1020), is incomplete: An activity may re-enforce neuronal formation and connection strengths according to “Hebb&#39;s rule”, but if the formation is unstable, it will disassemble or be taken over, recruited, or encroached upon by more stable neural configurations. The paradigm suggested is that there is a competition for neurons within the brain that must be included in the formation of learning and thought. In particular, the use of templates may be a highly unstable means for forming new neural sets for learning.  
         [0000]     Deficiencies in the MTR Method  
         [0038]     Research (see Langer, E., “The Illusion of Calculated Decisions”, in Beliefs, Reasoning, and Decision Making, R. Schank, E. Langer Eds.; De River, J., Field Theory of Human Science, NY, Gardner Press;  Attention and Performance XV,  MIT Press, 1994 “Measuring Recollection” and “Semantic Memory from a Neuropsychological Perspective”) has established that using templates, rules, and metaphors is not an optimal approach to training. The reasons for this are inherent in the neurodynamics of the human brain, many aspects of which are presented above. In lieu of a highly technical discussion, the following deficiencies are noted:  
         [0039]     Deficiencies in the Use of Templates  
         [0040]     Stroke templates have several significant limitations that retard the learning process.  
         [0041]     Stroke templates are rigid and inflexible, hence do not accommodate the need to adapt to the fact that no two shots are ever the same (as many professional players will attest to).  
         [0042]     Stroke templates do not provide insight into how the professional players produce their strokes or how they came about to develop their stroke style in the first place.  
         [0043]     Use of a stroke template promotes rigidity in body movements when the trainee is forced to use the template in situations where it cannot work. This keeps the student on edge and unable to relax. That is, because stroke templates are learned as a single unit, they cannot be easily modified or adapted to new circumstances.  
         [0044]     The use of stroke templates restricts the individual initiative of the trainee since the template is not subject to question.  
         [0045]     Stroke templates are based on a collective belief about what constitutes a correct stroke and are not founded on science. Hence, templates may contradict science and fact, and thus create barriers to the future development of the student.  
         [0046]     The use of stroke templates as a learning method contradicts current research on human cognition, which indicates that the human brain does not learn actions by memorizing templates, but rather by assembling mesoscopic components (i.e., components of intermediate scale, between microscopic neuronal memory and macroscale template memory) that can be assembled in various ways to form purposeful actions. (see, Walter J. Freeman III, Ph.D., MD. (2000) “Neurodynamics: An Exploration of Mesoscopic Brain Dynamics”, Springer; (2000) “Mesoscopic neurodynamics: From neuron to brain”,  Journal of Physiology  (Paris) 94: 303-322. In the tennis context, the components are elements of the stroke that can be understood separately from the stroke as a whole. Further, adaptation occurs by assembling components in various ways to fit the circumstances at hand. Thus adaptation is inhibited by the MTR method.  
         [0047]     The focus on stroke templates limits the ability of the instructor to factually analyze the trainee&#39;s problems and thus results in many problems going unsolved.  
         [0048]     Thus, teaching methods that rely on stroke templates do not permit extremely rapid learning that takes full advantage of how human brains operate since template-based teaching methods encourage exact copying, which is impossible and which also inhibits exploration of alternative methods of stroke production by the trainee.  
         [0049]     Stroke template methods are in conflict with natural learning as seen in children as they develop walking, running, and other physical skills.  
         [0050]     Deficiencies in the Use of Metaphors  
         [0051]     Metaphors are ambiguous and thus may be executed in thousands of ways most of which will be incorrect.  
         [0052]     Strokes learned from metaphors are easily forgotten.  
         [0053]     Metaphors lead to implementing ineffective and inefficient actions in place of effective and efficient actions.  
         [0054]     Metaphors, on the average, drastically delay the learning process and in most cases impede the process altogether.  
         [0055]     Metaphors, through their ambiguity, undermine most students&#39; self-confidence.  
         [0056]     Metaphors mean different things to different people.  
         [0057]     Deficiencies in the Rule Based Aspect of MTR Methods  
         [0058]     Rules are utilized in tennis instruction because it is widely believed that this is the only way trainees will learn strokes. This is a direct result of deficiencies in the knowledge of the tennis instructor community about how humans learn. The most rapid learning is associative, whereby the associations are to meaningful purposeful actions. For example, “keep your feet moving” is a rule that is widely taught, but it is not associated to any meaningful or purposeful result. The consequence is that trainees can be seen engaging in wasteful, meaningless foot shuffling because they are following a rule rather than making conscious decisions about what is the correct course of action in a given situation.  
         [0059]     Some further problems with the rule based instruction aspect of MTR methods are:  
         [0060]     Trainees become dependent on rules rather than reason and common sense  
         [0061]     Trainees lose their belief in the use of their individual initiative to resolve complex problems of play  
         [0062]     Skill development is inhibited by the constant fear of breaking the rules  
         [0063]     Students discard reasonable solutions of their own problems because they do not see how they fit into the rules  
         [0064]     Students become overly dependent on the instructor as the rule keeper  
         [0065]     Rule based learning prohibits exploration of alternatives  
         [0066]     Rule based learning restricts discovery of new methods  
       SUMMARY OF THE INVENTION  
       [0067]     To resolve the problems of the MTR method, it was necessary to set up a research program utilizing statistical hypothesis testing to narrow the possibilities for correct stroke production to a number that can be tested over a short time frame of a few years, to develop a method based on relevance and association, to ensure that each student can learn and understand the relevance of each components, so that each component would be learned at the fastest possible pace.  
         [0068]     The present invention, referred to as the EASI system, is a method for rapidly and efficiently teaching tennis strokes that addresses all of the above concerns which limit and restrict the ability of students to rapidly learn tennis strokes. The strokes are taught by only focusing on the development of the five special Action Components of the method. Each component is chosen and labeled based on its relevance. The Action Components are taught in the reverse order of their occurrence in the stroke, so that the student sees the relevance of each to the whole. Benefits of the EASI system over the MTR method are:  
         [0069]     The EASI system reduces learning time to a fraction of the MTR method (due to reversing the order in which components are taught) as compared to the template approach of the MTR system.  
         [0070]     According to the invention, the five Action Components of the tennis stroke are developed in reverse order, i.e., working in reverse from the strike to the backswing, or take-back, which allows the relevance of each Action Component to be established by the succeeding Action Component. Thus the student learns the relevance of what is being taught, which is much more helpful than simply learning by trying to follow a template.  
         [0071]     Each Action Component has a meaningful, easily understood purpose that can be explained by any practitioner and can be understood by the student after a short period of instruction.  
         [0072]     The Action Components do not themselves each necessarily have an end-use function, but rather are a set of approximations to actions or movements that can be adapted, modified, or improvised upon as circumstances require, or to fit any individual style. Further, they are to be viewed as a starting point for stroke development around which additional, novel modifications can evolve based on individual initiative.  
         [0073]     The Action Components, due to their relevance and method of development, may be retained in declarative memory (meaning that one can recall them on demand) and therefore can be recalled under pressure, unlike actions retained only in reflexive memory. This allows the student maximum independence from the instructor, so that the student has the potential for self-realization of their ability through exploration and imagination, without supervision.  
         [0074]     Visual Processing. The EASI system addresses the limitations of human visual processing by breaking down the unobservable portion of each stroke into a set of reproducible relevant action components.  
         [0075]     Associative memory and learning. The associative nature of human memory and learning is addressed by decomposing a stroke into relevant, result-producing components. Each component has a purpose and is not a simple abstract concept.  
         [0076]     The five Action Components and their functions can be summarized as follows: The strike component has the purpose of bringing the racquet into efficient contact with the ball. The acceleration component has the purpose of producing racquet head speed just before the strike. The rotation component has the purpose of rotating the body into a stable position from which the acceleration component will be most efficient. The contraction component has the purpose of positioning the elbow so that the acceleration components can produce maximum speed. The take-back component has the purpose of positioning the body and arm to begin the stroke.  
         [0077]     Reflexive memory. The problem of reflexive memory is addressed by the fact that the individual components and their order provide a declarative procedure to assist in carrying out actions when reflexive actions are degraded by tension and stress. Under pressure, it is possible to “forget” how to hit any rotely conditioned stroke (See Freeman, Societies of Brains, LEA publishers, page 124). However, if one has a declarative memory of the stroke, i.e., so that one can describe the component in words, it will be possible to restart one&#39;s reflexive memory, in much the same way Toastmasters train speakers to have a clear starting line for a speech to overcome their nervousness.  
         [0078]     Human memory. The EASI system addresses the inaccuracy of human memory by providing a system of associative recall for each component, which, along with a declarative procedure, provides a path that shortens the recall time of correct technique. The associative recall is established by choosing each component for its relevance, thus making it easy to recall.  
         [0079]     Intentional Actions. The EASI system addresses the complexity of the neurodynamics of intentional actions through the use of Action Components that may be adapted and modified to any circumstance and used in any measure.  
         [0080]     Disassembly and encroachment. The EASI system addresses the process of disassembly by providing a method for rapid assembly by using only the essential action components needed for a stroke. Encroachment is addressed by assuring that each component is as simple and relevant as possible and has a clear meaning in the mind of the student.  
         [0081]     Mystical and Social Interpretation of Random Events. The EASI system addresses the mystical interpretation of random events by conducting a factual analysis of errors.  
         [0082]     In short, each aspect of the EASI system is designed to remedy the deficiencies in one or more aspects of MTR methods, or any method that uses an aspect of the MTR method. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0083]     The invention will be better understood if reference is made to the accompanying drawings, in which:  
         [0084]      FIG. 1  illustrates the five stages of the forehand:  
         [0085]      FIG. 1 (A): The Take back or preparation  
         [0086]      FIG. 1 (B): The contraction  
         [0087]      FIG. 1 (C): The rotation  
         [0088]      FIG. 1 (D): The acceleration and  
         [0089]      FIG. 1 (E): The strike  
         [0090]     Each stage performs a separate task that has a purpose, making it easy to remember, practice and teach.  
         [0091]      FIG. 2 , comprising FIGS.  2 ( a )-( e ), similarly illustrates the five stages of the backhand drive. Each stage has the same purpose as with the forehand drive of  FIG. 1 . However, since this system does not contain rules, it is not necessary to execute or teach all stages.  
         [0092]      FIG. 3 , comprising FIGS.  3 ( a )-( c ), illustrates the forehand volley. In this figure the take back and contract stages are combined into one stage and the accelerate and strike stages are combined into one stage. Only the rotate stage remains. This Figure illustrates that the stages may be omitted or combined in any sequential manner to produce the needed stroke. Hence their combinations are not rules.  
         [0093]      FIG. 4  illustrates the straight-line interval of the strike stage needed to assure clean contact between racquet and ball.  
         [0094]      FIG. 5  illustrates a closer view of the acceleration stage than  FIG. 1D . Here the upper arm is used to provide a final burst of racquet speed. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0095]     With reference now to  FIG. 1 , the five stages of the tennis stroke shown for the forehand explain and illustrate the stages of the EASI Tennis system.  
         [0096]     Stage 1—The take back—This stage is not novel. It is only included as a necessary step to begin a full stroke. It consists of taking the racquet back as seen in  FIG. 1  (A).  
         [0097]     Stage 2—Contract—The contract stage is necessary to begin the movement of the racquet in a straight line (rather than a circular swing) forward toward the ball with the racquet parallel along the path of the ball, to a stable position with the elbow in front of the body plane. This is seen in  FIG. 1 (B). Note that the face of the racquet is parallel to the path of the ball which is coming from the direction the player is looking. This motion is accomplished by pulling from the shoulder and bending the elbow to the degree necessary to get the elbow in front of the body plane.  
         [0098]     Stage 3—Rotate—The rotate stage is necessary to move the face racquet from a position parallel to the path of the ball to a position of about 45 degrees skewed to the path of the ball. This speeds up the racquet face so that it begins to catch up with the butt of the racquet. This is seen in  FIG. 1 (C). This can be accomplished by rotating the shoulders or hips at the player&#39;s discretion.  
         [0099]     Stage 4—Accelerate—The accelerate stage is where the upper arm continues the rotation that starts in the rotate stage while significantly increasing the speed of the racquet while bringing the racquet face into complete alignment with the path of the oncoming ball, which may involve another 45 degrees of rotation. This is seen in  FIG. 1 (D). This is accomplished by upper arm rotation.  
         [0100]     Stage 5—Strike—The strike stage is where the racquet path is aligned so that entire racquet is moving forward without rotation and thus the entire racquet has no rotational component. This is when the ball is struck. This is seen in  FIG. 1 (E). This is accomplished by slightly extending the forearm toward the ball by using the shoulder and elbow joint.  
         [0101]     It should be emphasized that all systems of instruction are only discrete approximations of continuous, flowing movements and that the quality of the approximation is what is important. In this regard, the stages presented here are discrete approximations as well. Further, our system emphasizes learning them as components which can be adapted and modified to create a diverse range of strokes. This is necessary since no two strokes are ever the same and each stroke is uniquely constructed by the brain every time one is needed and it is designed to fit the circumstances. Templates teach rigid unadaptable strokes, where as a component-based approach inherently insures a greater degree of adaptability since this method is geared to how the brain takes in and uses information.  
         [0102]     It should also be noted that while no two strokes (especially at the professional level) are alike, all strokes contain to varying degrees the five components of the EASI Tennis system. Thus, the backhand stroke can be broken down into the same five stages, as illustrated in FIGS.  2 ( a )-( e ), and the forehand volley of FIGS.  3 ( a )-( c ) similarly contains a compressed version of the full forehand of  FIG. 1 . The serve, which is not separately illustrated, can be taught similarly.  
         [0103]     The method of teaching using the EASI Tennis system of the invention to a beginner is as follows.  
         [0104]     Instruction begins by explaining the five stages of the EASI Tennis System, their relevance, and what parts of the body are involved in their execution. After this overview, the instructor starts with the strike stage, that is, stage 5. The strike stage is taught first, as this is where the ball is struck and if this is not correct, nothing else can compensate for this deficiency. The relevance of the strike stage is that this is where the ball is struck so it is clear that our objective is to bring the racquet face into contact with the ball. It is the objective of this stage to move the racquet forward in a straight line 4″ to 8″ to ensure clean contact with the ball. This is illustrated in  FIG. 4 . As seen in the illustration, the elbow is in front of the body plane. After the strike stage is mastered sufficiently for the student to rally for 9-12 balls over the net at a time in the service court, the instruction moves on to the acceleration stage  4 .  
         [0105]     The acceleration stage is where the student learns how to produce racquet speed just before the strike occurs. The objective of the acceleration stage is to speed up the racquet at the last moment when the clearest view of the ball is obtained, and the racquet is most stable and controllable. This point of this stage is thus perfectly clear to the student. The acceleration is produced by upper arm rotation, which flows into the forearm extension of the strike stage. The acceleration is seen in  FIG. 5 .  
         [0106]     After the strike stage has been incorporated into the student&#39;s two-stage stroke we now develop the rotation stage  3  seen in  FIG. 1 ( c ). This can be approached by several means, but the simplest is to rotate the shoulders. This movement is sufficiently simple that it needs little illustration or explanation.  
         [0107]     After these three stages have been combined into a three-stage stroke, the contract stage  2  is added. This is illustrated by referring to  FIG. 1 ( b ). This is effectively a straight pull of the racquet by the butt from the take-back position in  FIG. 1 ( a ) to the contracted position in  FIG. 1 ( b ).  
         [0108]     Having accomplished each of these movements, the student is free to explore all their variations. As can be understood from our explanation, five stages are essential to incorporate all of the purposeful movements of a tennis stroke. Any attempt to add a sixth stage would be superfluous and any omission of a stage would result in a significant void in understanding how a stroke is produced. It is for these reasons and those explained above that the EASI Tennis Method uses at most five stages to describe a tennis stroke in a meaningful and relevant manner. However, fewer stages may be elected as the stages are components and any component may be omitted by the student at their discretion during play, e.g., in the forehand volley of  FIG. 3 ( a )-( c ). Further, for more advanced students, one may focus on only one component if it is found that all other components are intact.  
         [0109]     It will be apparent from the above that the method of the invention teaches tennis strokes in reverse, that is, starting from the successful strike and working backward in the stroke. In this way, the student gains understanding of the “why” of the various preparatory steps, e.g., the take-back is high so that one can execute the successive stages properly. This is to be contrasted with typical teaching methods, which position the racquet in the take-back position first, align the student&#39;s feet and shoulders, and so on, without providing a clear understanding for the purpose of such exercises.  
         [0110]     In order to see why this method is not obvious to someone skilled in the art of tennis instruction one only has to refer to the long history of tennis, and more recently, to the several organizations which set the present day standards of tennis instruction: the United States Professional Tennis Association (USPTA), the United States Tennis Association (USTA), the Professional Tennis Registry (PTR), and the European Registry of Tennis Professionals (ERTP). By inspection and review of these organizations&#39; instructional materials one sees at once that there is no method of instruction similar to the EASI Tennis method explained there. As these organizations profess to present the most advanced level of instruction available, our method, which is founded on neuroscience is clearly not obvious. One may go further and inspect the most well known and widely circulated tennis publications (printed or web based) and obtain a similar finding. Still further, one may review the comments on the EASI Tennis System of the invention found at www.tennisone.com to discover the remarkable novelty of our method. TennisONE is the most widely recognized source of tennis instruction in the world. The present inventor has been specifically invited to present the instructional method of the invention to the world on TennisONE because of its novelty, and more specifically, because it was thought by the Editor of TennisONE that these methods would be of great interest due to their unconventional nature and due to the degree to which the method of the invention overthrows all widely held and traditional views of tennis instruction. Due to the original and totally new approach to tennis instruction of the invention, the inventor has been invited to become a contributing editor to TennisONE, further confirming that the method of the invention was not obvious to those most skilled in the art of tennis instruction.  
         [0111]     Since its introduction to the world community in January of 2003 on TennisONE, the EASI Tennis method had gained wide recognition as a revolutionary method that rapidly accelerates the development of professional level tennis strokes.  
         [0112]     In addition to these observations, it is noted that the method of the invention required the confluence of three technologies to be conceived. First, high-speed photography was needed to resolve the motion from the take back stage to the strike stage since the human eye cannot do this. Thus the advent of readily available high-speed footage of top players was needed. However, this footage proved to provide too much information in that it is not clear how to organize it. Hence some means of organizing large quantities of dynamical systems data was needed. This leads to the second technology which is dynamical systems analysis, an area of expertise of the inventor. This allowed the possibility of identifying the important transitions within the data. But this was still insufficient. To derive the method one must answer the question of why each transition occurred. This analysis required knowledge of neuroscience, a second area of expertise of the inventor. By combining these three technology areas with an interest in playing tennis, it became possible to formulate the EASI Tennis method.  
         [0113]     It is further clear that subdividing the tennis stroke into five stages according to the invention addresses the issues of learning, as referred to above. For example, since each stage has a purpose, which is clearly and simply explained without requiring the student to memorize rules and templates, it is possible to remember these stages and to teach or practice them without ambiguity.  
         [0114]     Another advantage of the invention, which allows the student to become increasingly more independent of the instructor (and thus significantly reduce costs), it that it is possible for the student to practice each stage on a backboard, or even in one&#39;s home in spare time, and without using a ball.  
         [0115]     The above description and the drawings describe the invention in such detail that one skilled in the art may easily practice the invention. Moreover, minor variations in the inventive method will be apparent to those of skill in the art; the scope of the invention is accordingly not to be limited by the above exemplary description, but only by the following claims.