Patent Publication Number: US-8974313-B2

Title: Method and apparatus for determining an angle of attack from multiple ball hitting

Description:
BACKGROUND 
     The present invention relates to a system and method of determining an angle of attack of a golfer&#39;s swing, and in particular to a system and method of determining an angle of attack of a golfer&#39;s swing from multiple ball hitting. 
     Increased awareness and proliferation of golf equipment designed for particular levels of play has led to advances in matching a golfer with an appropriate golf club. Similarly, with advances in golf ball design, there has been increased interest in matching a golfer with an appropriate golf ball. 
     Golf club fitting has become well known and a routine service of golf pro shops. Typically, a combination of information about a golfer&#39;s physical characteristics, such as height, arm length, gender and age, and a golfer&#39;s swing characteristics, such as club head speed and angle of attack, are used to determine an appropriate club for a golfer. 
     Golf ball fitting is a newer process and generally uses a combination of subjective data gathered from a golfer questionnaire and objective swing characteristics, such as measurements of club head speed, ball speed, launch angle, angle of attack, backspin, side spin and total distance. 
     Thus, in both golf club fitting and golf ball fitting, there is a need in the art for a method and system for determining an angle of attack of a golfer&#39;s swing. Specifically, a method and system that will allow a golfer to conveniently and easily determine an angle of attack of the golfer&#39;s swing that can be useful for both golf club fitting systems and golf ball fitting systems. 
     SUMMARY 
     A method of determining an angle of attack of a golfer&#39;s swing from multiple ball hitting is disclosed. In one aspect, the invention provides a method for determining an angle of attack of a golf swing, comprising: providing a set of golf balls, where each golf ball in the set has a unique, known construction; measuring at least a first parameter associated with a first ball selected from the set when the first golf ball has been hit by a golf club; measuring at least a first parameter associated with each of the remaining golf balls in the set when each of the remaining golf balls have been hit by a golf club; and determining an angle of attack of a golf swing by correlating the measured parameters associated with each of the golf balls in the set to the angle of attack. 
     In another aspect, the invention provides a system for determining an angle of attack of a golf swing of a golfer, the system comprising: a set of golf balls, where each golf ball in the set has a unique, known construction; a monitoring apparatus for measuring parameters associated with the set of golf balls when each golf ball in the set has been hit by a golf club; and a processor for determining an angle of attack of a golf swing by correlating the measured parameters associated with each of the golf balls in the set to the angle of attack. 
     In another aspect, the invention provides a kit for determining an angle of attack of a golf swing of a golfer comprising a set of golf balls, where each golf ball in the set has a unique, known construction such that the angle of attack can be correlated using measured parameters associated with each of the golf balls in the set when hit by the golfer. 
     Other systems, methods, features and advantages of the invention will be, or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  is an isometric view of an exemplary embodiment of an apparatus for determining an angle of attack of a golf swing; 
         FIG. 2  is an isometric view of an illustration of a golf swing with a zero angle of attack, a golf swing with a negative angle of attack and a golf swing with a positive angle of attack; 
         FIG. 3  is an isometric view of an exemplary embodiment of golf balls of different known constructions; 
         FIG. 4  is an isometric view of an exemplary embodiment of a golfer hitting three golf balls of different known constructions; 
         FIG. 5  is an isometric view of an embodiment of a system for determining an angle of attack of a golf swing; 
         FIG. 6  is a flowchart of an exemplary embodiment of a method for determining an angle of attack of a golf swing; 
         FIG. 7  is a flowchart of an exemplary embodiment of a method for entering known golf club specifications; 
         FIG. 8  is a flowchart of an exemplary embodiment of an analysis module determining an angle of attack of a golf swing; 
         FIG. 9  is an isometric view of an embodiment of a kit for determining an angle of attack from multiple ball hitting; 
         FIG. 10  is an isometric view of an embodiment of a ball fitting system interface; 
         FIG. 11  is an isometric view of an embodiment of a ball fitting system interface for entering angle of attack data; and 
         FIG. 12  is an isometric view of an embodiment of a ball fitting system. 
     
    
    
     DETAILED DESCRIPTION 
     One element that determines the ball flight path and other characteristics associated with hitting a golf ball is the position in the arc of the swing at which the golf club strikes the golf ball. This is known as the angle of attack. The angle of attack generally describes the swing plane of a golfer. A level swing or zero angle of attack is where impact is made at the very bottom of the swing arc. 
     A golfer may instead hit the ball at a slight angle. If a golfer hits a ball at a slight upward angle, i.e., while the club is moving toward the top of the swing arc, this is known as a positive angle of attack. If a golfer hits a ball at a slight downward angle, i.e., while the club is still moving toward the bottom of the swing arc, this is known as a negative angle of attack. In some cases, a negative angle of attack may be desired for a golf shot. This can be true when an iron is used to strike the ball. A negative angle of attack produces a larger degree of backspin than a ball hit at an upward angle or a zero angle. This may produce greater control for a golfer hitting into a green. 
     A golfer will typically hit a driver, on the other hand, at a low or even zero angle of attack. Since balls hit with a driver are usually being hit for distance into a fairway, relatively low spin is typically desirable. A ball with low backspin tends to flatten when flying, and, therefore, stays true to the flight path. Low backspin can allow a drive to fly further. Additionally, a ball with low backspin can roll further after contact with the ground, which is frequently desirable on drives, particularly for less experienced golfers. 
     Generally, an angle of attack of a golfer&#39;s swing can have a direct influence on a golfer&#39;s performance. A “flatter” swing will generally improve both distance and accuracy with a driver. A shallow angle of attack, i.e., a swing with angle of attack close to zero, results in a more solidly hit ball with less spin producing a longer and straighter shot. Divots are one way golfers typically review their angles of attack when hitting with their irons, since a golfer who hits with a shallow angle of attack will generally leave shallow divots while a golfer who hits with a steeper angle of attack, i.e., a swing with a large negative angle of attack, will generally leave deeper divots. Proficient players, such as Tour players, will generally have a shallow angle of attack, and higher handicap players will generally have a steeper angle of attack. Golf balls can be designed to help compensate for these swing mechanics associated with an angle of attack. 
     Knowing a golfer&#39;s angle of attack can assist in selecting an appropriate ball. This data can assist in selecting a ball that will produce a desired response when struck with different clubs. The present method and system can be used as a component in the system disclosed in copending and commonly owned U.S. Pat. No. 8,758,169, entitled “Method and System for Golf Ball Fitting Analysis”, and filed on Jul. 7, 2009, which is incorporated herein by reference. 
       FIG. 1  is a view of an exemplary embodiment of an apparatus that is configured to determine an angle of attack of a golf swing. Referring to  FIG. 1 , an angle of attack may be determined using a launch monitor  104  to measure parameters associated with a golf ball  100  hit by a golf club  102 . In this embodiment, launch monitor  104  includes a video camera to measure the parameters associated with golf ball  100  hit by golf club  102 . In some embodiments, launch monitor may include multiple cameras to measure parameters associated with a golf ball and a golf club. In some cases, the launch monitor may include one or more CCD cameras. In other cases, launch monitor may also include a radar swing speed detector, a motion capture device, or any number of such devices. Various other optical, photographic, infrared, ferro-magnetic or laser sensors or measuring devices are all contemplated to be used to measure the parameters associated with a golf ball hit by a golf club. 
       FIG. 2  illustrates three exemplary views of an angle of attack of a golfer&#39;s swing. As illustrated in the three views, golf club head  102  travels toward golf ball  100  in path  200 . At the point of contact, golf ball  100  travels along ball flight path  202 . Generally, the angle of attack a represents the angle of the club head&#39;s path as it travels toward, and then makes contact with, the golf ball. The angle of attack is determined by the golfer&#39;s swing mechanics. As a reference point, most golf instruction refers to a zero angle of attack as meaning that the club head is traveling level with the ground at impact. This is sometimes called a sweeping angle of attack.  FIG. 2  illustrates a zero angle of attack  204 . 
     A golfer&#39;s swing can also produce a negative angle of attack. As illustrated in  FIG. 2 , the golf club head  102  comes down at golf ball  100  along path  200  and moves below the golf ball after impact, creating a negative angle of attack  206 . A golfer&#39;s swing can also produce a positive angle of attack. As illustrated in  FIG. 2 , the golf club head  102  travels below golf ball  100  along path  200  and moves up through impact, creating a positive angle of attack  208 . 
     When a golf ball is hit by a golf club, the force of the impact deforms the golf ball. In the process, the kinetic energy of the golf club is transferred to the golf ball through the impact. The amount of energy transferred from the golf club to the golf ball is represented by the coefficient of restitution (COR). The COR is expressed as a number between 0 and 1, where 0 represents an inelastic impact where all the energy of the impact is absorbed and 1 represents an elastic impact where all the energy of the impact is transferred. 
     Golf balls can have known construction and response properties, including, but not limited to coefficient of restitution (COR), construction type, compression, dimple pattern, tendency to spin, and other properties. These properties can be different depending on the composition and configuration of the golf ball. 
     Golf balls can be made in various configurations and can be composed of a variety of materials. Golf balls configurations may include, but are not limited to two piece, three piece or four piece configurations. Each configuration includes a cover. In some cases, the cover material may include, but is not limited to urethane, balata, synthetic balata, Surlyn®, elastomer and other materials. The inner composition of a golf ball may include a core, a mantle and additional core or mantle layers, depending on whether the golf ball is a two piece, three piece or four piece configuration. The inner composition of a golf ball may include a variety of materials including, but not limited to: natural rubber, balata, synthetic rubber, plastics, thermoplastics, polymers, elastomers, resins and other materials and combinations of materials. 
     According to one exemplary embodiment illustrated in  FIG. 3 , a number of golf balls with different known constructions are provided. Referring to  FIG. 3 , a two piece golf ball  310  is illustrated with a synthetic cover material and a rubber core  312 , a three piece golf ball  320  is illustrated with a synthetic cover material, a polymer core  324  and a rubber mantle  322 , and a three piece golf ball  330  is illustrated with a synthetic cover material, a larger polymer core  334  and a rubber mantle  332 . 
     Also referring to  FIG. 3 , a three piece golf ball  340  is illustrated with a synthetic cover material, a rubber core  344  and a polymer mantle  342 , a three piece golf ball  350  is illustrated with a synthetic cover material, a smaller rubber core  354  and a polymer mantle  354 , and a two piece golf ball  360  is illustrated with a synthetic cover material and a polymer core  362 . In this embodiment, a set  300  of golf balls with known constructions is shown. In other embodiments, golf balls of known constructions may be composed of different materials and in different configurations than those illustrated in  FIG. 3 . 
     Given a golf ball of known construction and response properties, a correlation can be made between the response properties and an angle of attack of a golf swing. In some cases, this correlation can be generated by using a golf swing robot to hit each of the golf balls of known construction multiple times and with various angles of attack and gather measured data associated with the hit golf balls. Golf swing robots are well-known in the art, and any type of robot capable of consistently swinging a golf club according to a programmed set of instructions may be used. In some embodiments, the result can include a database containing data associated with each of the golf balls with different known constructions and response properties correlated to the angle of attack. In other cases, analytic software may be used to execute a program that can correlate the measured data associated with the golf balls of different known constructions to an angle of attack. 
     An angle of attack of a golfer&#39;s swing may be determined using measured parameters associated with a golf ball of known construction hit by a golf club.  FIG. 4  illustrates an exemplary embodiment of a golf club  102  hitting a first golf ball  400 , a second golf ball  402  and a third golf ball  404 , each golf ball with different known constructions. As shown in  FIG. 4 , for each golf ball of known construction, the club head speed v of the golf club  102  and the backspin θ of the golf ball after the golfer (not shown) strikes the golf ball with the golf club  102  are measured. In this embodiment, the measured parameters include club head speed and backspin. In other embodiments, other parameters may be measured. Measured parameters may include, but are not limited to: club head speed, ball speed, launch angle, angle of attack, backspin, side spin, total distance and other parameters associated with a golf ball or a golf club. No specific device or method of measuring the parameters associated with the golf balls is essential. Many devices and systems for measuring parameters, including club head speed and backspin, are well-known in the art, and any of these devices and systems can be used in the present system. For example, any standard launch monitor may be used. 
       FIG. 5  illustrates an exemplary embodiment of a system for determining an angle of attack of a golf swing from multiple ball hitting. System  500  can include a launch monitor  104  for measuring parameters associated with multiple golf balls with different known constructions, including a first golf ball  502 , a second golf ball  504 , a third golf ball  506 , and a last golf ball  508  when hit by a golf club. System  500  also can include a computer  516  for receiving measured parameters associated with first golf ball  502 , second golf ball  504 , third golf ball  506 , and last golf ball  508  from launch monitor  104 . In some embodiments, computer  516  also may receive data associated with a golf club from club module  518 . Computer  516  may be provided in various hardware and software configurations, including, but not limited to: a processor, a smart phone or other portable device including a processor, a terminal connected to a server over a network, and other hardware or software configurations for processing data. 
     In one embodiment, computer  516  may communicate with an analysis module  510  for correlating the measured parameters received from launch monitor  104  to an angle of attack. In some embodiments, analysis module may be included in the computer  516 . In other embodiments, analysis module may be connected to the computer  516  in various ways, including, but not limited to: a wire, a physical connector, a wired network, a wireless network or other wired or wireless communication methods. Analysis module  516  may include, but is not limited to: a processor, a computer, a server, a smart phone or other portable device including a processor, a terminal connected to a server over a network, and other hardware or software configurations for processing data. 
     Referring to  FIG. 5 , in this exemplary embodiment, analysis module  510  can include a database  512  and analytic software  514  used to determine the angle of attack. Analysis module  510  can receive the measured parameters from first golf ball  502 , second golf ball  504 , third golf ball  506 , and last golf ball  508  from computer  516 . In some cases, analysis module  510  may also receive data associated with a golf club received by computer  516  from club module  518 . Analysis module  510  may include a processor configured to access database  512 , execute analytic software  514 , either or both, to determine the angle of attack from the received information. Analysis module  510  can transmit the determined angle of attack to computer  516  for output  520 . In one exemplary embodiment, the angle of attack is output for use in a ball fitting system  522 . In other embodiments, the angle of attack may be used for other applications, including a golf club fitting system and a golfer profile database. 
       FIG. 6  illustrates a flowchart of an exemplary embodiment of a method  600  of determining an angle of attack from multiple golf ball hitting. The order of the steps illustrated in  FIG. 6  is exemplary and not required. Referring to  FIG. 6 , in a first step  602 , according to this embodiment a set of n golf balls of different known constructions are provided. From the set of n golf balls, a subset of x≦n golf balls with different known constructions are selected in a second step  604  for a golfer to hit. In some embodiments, the choice of golf balls selected may be entered into the system to allow the known characteristics associated with the selected golf balls to be retrieved. 
     In some cases, criteria may be provided to allow subset x of golf balls with different known constructions to be selected for a particular golfer. In some embodiments, the criteria may include a characteristic of the golfer. Characteristics of the golfer that may be used to determine the criteria include, but are not limited to: age, gender, skill level, handicap, data from a golfer profile database, answers from a questionnaire, swing characteristics and other characteristics of a golfer. 
     In some embodiments, the criteria for selecting a subset of golf balls with different known constructions for a particular golfer may be provided in a guide. In other embodiments, the criteria can be shown on a display. In other embodiments, the criteria may be input into a computer. Still other embodiments of criteria for selecting the subset of golf balls may be possible, including selecting a random subset of golf balls, selecting golf balls closely matching a golfer&#39;s preferred golf ball and other objective or subjective criteria. 
     Referring to  FIG. 6 , in some embodiments specifications of a golf club being used to hit the golf balls can be entered in optional third step  606 . Golf club  102  may be any type of club known in the art. In some embodiments, the golfer may be asked to hit with a test club, which may be a driver, an iron, or any type of club. In other embodiments, golf club  102  may be the golfer&#39;s own club. The golf club  102  may be a club of known specifications, including having a known coefficient of friction of the club face and other known properties. 
     After the selected ball and, optionally, the club specifications have been inputted to the system, according to the exemplary embodiment illustrated in  FIG. 6 , in a fourth step  608  a golfer (not shown) hits a first ball of known construction. At least spin rate and club head speed associated with the first hit ball can be recorded in fifth step  610 . In sixth step  612 , the system determines whether sufficient data associated with the first golf ball has been recorded. If there is not sufficient data, the golfer returns to fourth step  608  to again hit the first golf ball. In some cases, data may not be sufficient if the parameters associated with the golf ball have not been measured or have not been recorded within acceptable tolerances. In other cases, data may not be sufficient if the method requires more than a single impact per golf ball for determining the angle of attack. Other reasons for determining that the data is not sufficient are also possible, such as if the golfer is unhappy with the feel of his or her shot. 
     As illustrated in  FIG. 6 , if there is sufficient data, the system moves to step  614  where the golfer hits a second golf ball of a different known construction. In step  616 , at least spin rate and club head speed associated with the second hit ball can be recorded. As described above with regard to the first ball, if there is not sufficient data recorded for the second ball, the golfer returns to step  614  to again hit the second ball. If there is sufficient data, the golfer proceeds to hit the next golf ball of a different known construction. The process can continue until a golfer hits golf ball x of different known construction in a ninth step  620 . At least spin rate and club head speed associated with hit ball x can be recorded in a tenth step  622 . At an eleventh step  624 , the system determines if there is sufficient data recorded of ball x. If there is not sufficient data recorded for ball x, the method returns to ninth step  620  and the golfer again hits ball x. If there is sufficient data, twelfth step  626  provides a check to make sure at least x≧3 golf balls with different known constructions have been hit. In this exemplary embodiment, at least three golf balls of different known constructions may be hit by a golfer. In other embodiments, more or fewer golf balls with different known constructions may be hit by a golfer. 
     Referring to  FIG. 6 , in this embodiment, if at least the minimum number of golf balls with different known constructions have not been hit, the method returns to the process described in ninth step  620 , tenth step  622 , and eleventh step  624  for ball x+1 in thirteenth step  628 . If the minimum number of golf balls has been met, the angle of attack for the golfer is determined using the recorded data associated with the hit golf balls in final step  630 . 
       FIG. 7  illustrates an exemplary embodiment of a method  700  of determining club specifications of a golf club. The order of the steps illustrated in  FIG. 7  is exemplary and not required. As described above, a golf club used for hitting multiple golf balls of different known constructions may be any type of club known in the art. At first step  702 , the system determines whether the club is of known specifications. If the club is of known specifications, the process moves to a second step  704  to determine whether the club is a test club. In some cases, a test club of known specifications may be provided on the premises where the ball hitting apparatus is located. 
     If the club is not a test club, the process can determine that the golf club is the golfer&#39;s own club at third step  706  and can proceed to check whether there exists a stored golfer profile that includes club specifications at fourth step  708 . If there is no stored golfer profile, or the profile does not contain club specifications, the process can move to a fifth step  710  to check whether the golfer&#39;s club is listed in a database of known club specifications. In some cases, the database may be populated with club specifications of a variety of different golf clubs used by golfers. In other cases, the database may be capable of querying another database or website over the Internet. 
     In the exemplary embodiment illustrated in  FIG. 7 , if the process determines that club specifications are available at any of second step  704 , fourth step  708 , or fifth step  710 , the club specifications are retrieved at a sixth step  714 . Referring back to first step  702 , if the club is not of known specifications, at step  712  the method can check whether the club specifications can be measured. In some cases, specifications of a golf club can be measured using other test equipment that may be located on the premises. Test equipment for measuring specifications of a golf club is well known in the art. The measured club specifications from step  712  or the retrieved club specifications from step  714  can be output at step  718 . The output club specifications from step  718  may be entered at step  606  into a process  600  for determining an angle of attack. If club specifications are not available at step  710  or  712 , the process ends at step  716 . 
       FIG. 8  illustrates an exemplary embodiment of a method  800  for an analysis module  510  to determine an angle of attack  520 . Analysis module  510  may be configured to determine an angle of attack  520 . Analysis module  510  may receive first measured parameter(s)  610  associated with a first golf ball of known construction, second measured parameter(s)  616  associated with a second golf ball of known construction, and third measured parameter(s)  622  associated with a third golf ball of known construction. In one embodiment, analysis module  510  receives measured parameters associated with at least x number of golf balls with different known constructions. In an exemplary embodiment, x is at least three. In other embodiments, measured parameters associated with more or fewer golf balls with different known constructions may be provided to analysis module  510 . 
     In the exemplary embodiment shown in  FIG. 8 , the first measured parameter(s)  610 , the second measured parameter(s)  616 , and third measured parameter(s)  622  can include spin rate and club head speed. The spin of a golf ball is the rotation of a golf ball while in flight. Spin includes rotation against the direction of flight, i.e., backspin, and rotation sideways to the direction of spin, i.e., side spin. The spin rate of a golf ball is the speed that the golf ball rotates on its axis while in flight. Typically, the spin rate is measured in revolutions per minute (rpm). Club head speed is a measurement of the velocity of the club head of a golf club at the bottom of a swing. In other embodiments, the measured parameters may include any parameters associated with a golf ball as described above. In some embodiments, analysis module  510  also may optionally receive club specifications  606  of a golf club. 
     Referring to  FIG. 8 , analysis module  510  receives the first measured parameter(s)  610 , the second measured parameter(s)  616 , and third measured parameter(s)  622 . In some embodiments, at step  802  analysis module may look up a correlation with the measured parameters to an angle of attack in a database. In other embodiments, analytic module  510  may include a processor to execute analytic software at step  804  to correlate the measured parameters to an angle of attack. In other embodiments, an analysis module may both access a database and execute analytic software to determine the angle of attack from the measured parameters. In some cases, analysis module  510  also may use data associated with club specifications  606  with the database or analytic software to determine the angle of attack. 
       FIG. 9  illustrates an exemplary embodiment of a kit  900  for determining an angle of attack of a golf swing of a golfer from multiple ball hitting. As illustrated in  FIG. 9 , kit  900  can include a set  902  of golf balls with unique, known constructions. Set  902  may include a first golf ball  904  of a first known construction, a second golf ball  906  of a second known construction, a third golf ball  908  of a third known construction, a fourth golf ball  910  of a fourth known construction, a fifth golf ball  912  of a fifth known construction, and a sixth golf ball  914  of a sixth known construction. Kit  900  may also include a selection guide  916  for selecting a subset of the set  902  of golf balls for a golfer to hit. 
     In the exemplary embodiment illustrated in  FIG. 9 , selection guide  916  can include criteria based on an age and a gender of a golfer. In other embodiments, selection criteria for determining a subset of golf balls with known constructions may include one or more different characteristics of a golfer as described above. In this exemplary embodiment, selection guide  916  can include a subset for an adult male  918  of golf balls with different known constructions. Similarly, selection guide can include other subsets of golf balls with different known constructions for an adult female  920 , a teen male  922  and a child  924 . 
     Referring to  FIG. 9 , in this embodiment, each subset may include different groups of golf balls with different known constructions. For example, selection guide  916  can list subset (CEF) for an adult male and subset (ABC) for a child  924 . In some cases, the subset can be chosen based a likely preference for a particular type of golf ball. In other cases, subset categories may be chosen based on a variety of objective or subjective criteria more fully described above. 
     Kit  900  also may include a storage medium  926  containing an angle of attack database  928  correlated to the set of golf balls  902  included in the kit  900 . In an exemplary embodiment, storage medium  926  containing angle of attack database  928  is a CD-ROM disc. In some embodiments, the storage medium may be any machine-readable media, including, but not limited to: flash memory, other types of media such as magnetic devices, optical devices or the like. In other embodiments, an angle of attack database may be provided in a chart or other printed format. In other embodiments, the database may include a code for allowing a user to access remotely stored data associated with the set of golf balls of different known constructions correlated to an angle of attack. 
     In various embodiments, the kit for determining an angle of attack of a golf swing from multiple ball hitting can be used by an operator. In some embodiments, the operator may be associated with a pro shop or other retail location. In some cases, the kit can be used in conjunction with existing equipment. In other cases, the kit may include additional equipment to allow the parameters associated with the golf balls of different known construction to be measured. In other embodiments, the operator may be a consumer. In some cases, the consumer may use the kit to determine an angle of attack of the consumer&#39;s golf swing. 
     In some embodiments, the kit may include a set of replacement golf balls of different known constructions. In some cases, the replacement golf balls of different known constructions may be a particular subset of golf balls of different known constructions. In some embodiments, the kit of replacement golf balls of different known constructions may include a replacement angle of attack database or a replacement selection guide or both. Various combinations for replacement kits are contemplated by different embodiments. 
       FIGS. 10 and 11  illustrate an exemplary embodiment of an angle of attack obtained from multiple ball hitting being used as part of a ball fitting system. In one embodiment, an angle of attack is used as a component in a ball fitting system disclosed in copending and commonly owned U.S. Pat. No. 8,758,169, entitled “Method and System for Golf Ball Fitting Analysis”, and filed on Jul. 7, 2009, discussed and incorporated by reference above.  FIG. 10  illustrates a sample entry screen  1000  in which an operator can choose between a new player or an existing player. In some cases, an existing player may have a profile stored in a database or on a removable media to allow the computer to retrieve the player information.  FIG. 11  illustrates a sample screen shot  1100  of a computer displaying the results of obtained angle of attack data of a golfer. As shown in  FIG. 11 , the obtained angle of attack data may be graphically represented to the golfer to provide a visual depiction of the obtained data for golf balls of different known constructions. 
       FIG. 12  illustrates a schematic diagram of an exemplary embodiment of a system  1200  for performing the ball fitting method. The system  1200  can include a computer  1202  running software to collect the inputs and perform the calculations discussed herein. Computer  1202  may be functionally connected via hardwire or wirelessly, to various measurement equipment such as a launch monitor  1204 , a radar swing speed detector  1206 , a motion capture device  1208  or any number of such devices. In some cases, putting monitors could be used to capture the attack angle of the club and launch angle. Various other optical, photographic, infrared, ferro-magnetic or laser sensors or measuring devices are all contemplated to be used to collect the objective data of the golfer. 
     While the software for performing the method of ball fitting could be run on a standalone general purpose computer  1202 , it is also contemplated that computer  1202  could be a server or connected to the Internet  1212 . In some embodiments, computer  1202  may include, but is not limited to: a desktop computer, a portable computer, a server, a smart phone or other portable device including a processor, a terminal connected to a server over a network, and other hardware or software configurations for processing data. Computer  1202  could be a terminal to use the method of ball fitting online or remotely from where the software resides or is hosted. The computer  1202  may also include a keyboard, a mouse, and a monitor controlled by a display card. The computer  1202  also may include a hard disk or other fixed, high density media drive, and a removable media device drive into which a removable magneto-optical media such as a disk is inserted and read and/or written to. These discrete components are connected using an appropriate device bus. The computer  1202  may also be connected to a printer (not shown) to provide printed listings of any of the inputs, intermediate calculations, and outputs associated with a golfer, a golf ball or a golf club. Examples of computer readable media present in the system illustrated in  FIG. 12  include the memory, the hard disk, and the removable media. Stored on any one or a combination of computer readable media, the described method and system includes software for controlling the hardware of the computer and for enabling the computer to interact with a user. The software may include, but is not limited to, device drivers, operating systems and user applications. Computer readable media further includes the computer program product for determining an angle of attack. 
     It is also contemplated that a removable media device such as flash memory  1210  could be used with computer  1202  to store a golfer&#39;s inputs and information. This would enable a golfer to reevaluate after some time has lapsed to determine how their game has changed over time. This would also enable a golfer to prepare to play in a different location with different altitude and climate by changing only those inputs to their stored data. This would also enable portability of their information in case of travel or relocation. 
     Although the removable memory is illustrated as flash memory, other types of media such as magnetic devices, optical devices, and the like are also within the scope of the invention. 
     It is also contemplated that the method of determining an angle of attack could be part of a broader athlete data storage, analysis and retrieval system in which vital statistics and game statistics are stored for review or analysis by various programs, and to recommend new equipment suited to an athlete&#39;s game. Such programs or data could be run on hand held devices as smart phones or other personal computing devices, with the possibility of sharing the data by users who have given each other authorization to view the data. 
     While various embodiments of the invention have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.