Method for selecting golf club

1. A fitting method of a golf club, comprising the steps of:

performing the following steps by a processor;

preparing a relationship C in which a face angle at or before impact and a hitting result are considered when a plurality of golf players swing using a plurality of golf clubs with different head physical property values;

obtaining measurement result of the face angle by a subject (golf player) hitting a ball with a test club; and

determining a head physical property fitted to the subject on the basis of the relationship C and the measurement result of the face angle,

wherein:

the relationship C is a relational expression F1,

the relational expression F1 is a relational expression F12 of the face angle and the head physical property,

in the relational expression F12, correlation Rx of the hitting result and the face angle is considered,

the head physical property is a centroid position of a head, a lie angle, a bulge on the face surface or a moment of inertia of the head, and

the relational expression F12 is a relational expression in which the greater the face angle to be measured is, the more at the heel side the recommended centroid position of head is.

2. The fitting method according to claim 1 , wherein in the relational expression 12, a preferred hitting result at a standard centroid position Gh of the head is reflected.

3. The fitting method according to claim 1 , wherein in the relational expression F12, more than two hitting results are considered.

4. The fitting method according to claim 3 wherein the relational expression F12 is created by modifying a relational expression based on a first hitting result, on the basis of a second hitting result.

5. The fitting method according to claim 4 wherein the modification based on the second hitting result is such a modification that the second hitting result is preferable at the standard centroid position Gh of the head.

6. The fitting method according to claim 4 wherein

the first hitting result is a direction of a hit ball; and

the second hitting result is a flight distance.

7. A fitting method of a golf club, comprising the steps of:

performing the following steps by a processor;

preparing a relationship C in which a face angle at or before impact and a hitting result are considered when a plurality of golf players swing using a plurality of golf clubs with different head physical property values;

obtaining measurement result of the face angle by a subject (golf player) hitting a ball with a test club; and

determining a head physical property fitted to the subject on the basis of the relationship C and the measurement result of the face angle,

wherein:

the relationship C is a relational expression F1,

the relational expression F1 is a relational expression F12 of the face angle and the head physical property,

in the relational expression F12, correlation Rx of the hitting result and the face angle is considered,

the head physical property is a centroid position of a head, and

in the relational expression F12,

the measured face angle is made a first input variable:

a value showing a relationship of a centroid position D1 of a head of the test club and the standard centroid position Gh of the head is made a second input variable; and

the centroid position Y of the head fitted to the subject is made a result variable.

8. The fitting method according to claim 1 wherein the head physical property is a centroid position of a head.

9. The fitting method according to claim 1 wherein the relational expression F1 is a linear expression.

10. The fitting method according to claim 1 wherein the hitting result is a right/left direction in which a ball flies.

11. A fitting method of a golf club comprising the steps of:

performing the following steps by a processor;

acquiring measurement data and hitting results of a plurality of golf players using a plurality of golf clubs with different values of head physical properties;

obtaining a characteristic value on the basis of the measurement data;

determining an indicator for selecting a head of a golf club from the characteristic value and the hitting results;

obtaining a relational expression F1 of the indicator and the hitting results for each value of the head physical properties;

obtaining measurement result corresponding to the indicator by a subject (golf player) hitting a ball with a test club; and

determining a head physical property fitted to the subject on the basis of the relational expression F1 and the measurement result, wherein

in the step of obtaining multiple pieces of measurement data and hitting results,

the multiple pieces of measurement data are obtained from swings of the golf players and hit balls of the swings, and

in the step of determining an indicator,

when the hitting results are made an objective variable, the characteristic value and values of the head physical properties are made an explanatory variable, and the characteristic value has a statistically significant relation with the hitting results, the characteristic value is determined as the indicator,

wherein:

the hitting result is a flight distance of a ball,

the head physical property is a centroid position of a head, a lie angle, a bulge on the face surface or a moment of inertia of the head, and

the characteristic value is a face angle before impact or at impact.

12. The fitting method according to claim 11 wherein

in the step of determining an indicator, a plurality of indicators is determined, and the method further comprising the steps of:

calculating an accuracy rate of values of head physical properties determined from the plurality of indicators; and

selecting an indicator to be used in fitting of a golf club, on the basis of the accuracy rate, wherein

in the step of calculating an accuracy rate of values of head physical properties,

a value Xa of the fit head physical property is selected based on a relational expression F1 of the indicator and the hitting results,

a value Xb of the fit head physical property is determined based on values of hitting results obtained from the swings, and

a golf player rate for which the value Xa and the value Xb match is calculated, and the rate is made an accuracy rate, and

in the step of selecting an indicator to be used in fitting of a golf club,

an indicator for which the accuracy rate is highest is selected to be an indicator to be used in fitting.

13. A fitting method of a golf club comprising the steps of:

performing the following steps by a processor;

acquiring measurement data and hitting results of a plurality of golf players using a plurality of golf clubs with different values of head physical properties;

obtaining a characteristic value on the basis of the measurement data;

determining an indicator for selecting a head of a golf club from the characteristic value and the hitting results;

obtaining a relational expression F1 of the indicator and the hitting results for each value of the head physical properties;

obtaining measurement result corresponding to the indicator by a subject (golf player) hitting a ball with a test club; and

determining a head physical property fitted to the subject on the basis of the relational expression F1 and the measurement result, wherein

in the step of obtaining multiple pieces of measurement data and hitting results,

the multiple pieces of measurement data are obtained from swings of the golf players and hit balls of the swings, and

in the step of determining an indicator,

when the hitting results are made an objective variable, the characteristic value and values of the head physical properties are made an explanatory variable, and the characteristic value has a statistically significant relation with the hitting results, the characteristic value is determined as the indicator,

wherein

the hitting result is a right/left direction in which a ball flies;

the head physical property is a centroid position of a head, a lie angle, a bulge on the face surface or a moment of inertia of the head; and

the characteristic value is a face angle before impact or at impact.

14. A fitting method of a golf club comprising the steps of:

performing the following steps by a processor;

acquiring measurement data and hitting results of a plurality of golf players using a plurality of golf clubs with different values of head physical properties;

obtaining a characteristic value on the basis of the measurement data;

determining an indicator for selecting a head of a golf club from the characteristic value and the hitting results;

obtaining a relational expression F1 of the indicator and the hitting results for each value of the head physical properties;

obtaining measurement result corresponding to the indicator by a subject (golf player) hitting a ball with a test club; and

determining a head physical property fitted to the subject on the basis of the relational expression F1 and the measurement result, wherein

in the step of obtaining multiple pieces of measurement data and hitting results,

the multiple pieces of measurement data are obtained from swings of the golf players and hit balls of the swings, and

in the step of determining an indicator,

when the hitting results are made an objective variable, the characteristic value and values of the head physical properties are made an explanatory variable, and the characteristic value has a statistically significant relation with the hitting results, the characteristic value is determined as the indicator,

wherein

the head physical property is a centroid position of a head,

the indicator is a face angle before impact or at impact,

a value X of a face angle for which an absolute value of a direction in which a ball flies is 0 is determined for each of the value Y of the centroid position of the head,

an approximate expression which satisfies a relationship of the value Y of each centroid position of a plurality of heads and the value X of the face angle

Y=A 1 ·X+B

(coefficient A1 and intercept B are a constant)

is determined, and

the approximate expression is the relational expression F1.

15. The fitting method according to claim 14 wherein the intercept B is modified based on a relationship of the flight distance of the ball and the value of the face angle.

16. An analysis method of swings of a golf club, comprising steps of:

performing the following steps by a processor;

acquiring multiple pieces of measurement data and hitting results of a plurality of golf players using a plurality of golf clubs with different values of head physical properties;

obtaining a characteristic value on the basis of the measurement data;

determining an indicator for selecting a head of a golf club from the characteristic value and the hitting results; and

obtaining a relational expression F1 of the indicator and the hitting results for each value of the head physical properties; wherein

in the step of obtaining multiple pieces of measurement data and hitting results,

the multiple pieces of measurement data are obtained from swings of the golf players and hit balls of the swings, and

in the step of determining an indicator,

when the hitting results are made an objective variable, the characteristic value and values of the head physical properties are made an explanatory variable, and the characteristic value has a statistically significant relation with the hitting results, the characteristic value is determined as the indicator,

wherein:

the hitting result is a flight distance of a ball,

the head physical property is a centroid position of a head, a lie angle, a bulge on the face surface or a moment of inertia of the head, and

the characteristic value is a face angle before impact or at impact.

17. The analysis method according to claim 16 wherein

in the step of determining an indicator, a plurality of indicators is determined, and the method further comprising the steps of:

calculating an accuracy rate of values of head physical properties determined from the plurality of indicators; and

selecting an indicator to be used in fitting of a golf club, on the basis of the accuracy rate, wherein

in the step of calculating an accuracy rate of values of head physical properties,

a value Xa of the fit head physical property is selected based on a relational expression F1 of the indicator and the hitting results,

a value Xb of the fit head physical property is determined based on values of hitting results obtained from the swings, and

a golf player rate for which the value Xa and the value Xb match is calculated, and the rate is made an accuracy rate, and

in the step of selecting an indicator to be used in fitting of a golf club,

an indicator for which the accuracy rate is highest is selected to be an indicator to be used in fitting.

18. An analysis method of swings of a golf club, comprising steps of:

performing the following steps by a processor;

acquiring multiple pieces of measurement data and hitting results of a plurality of golf players using a plurality of golf clubs with different values of head physical properties;

obtaining a characteristic value on the basis of the measurement data;

determining an indicator for selecting a head of a golf club from the characteristic value and the hitting results; and

obtaining a relational expression F1 of the indicator and the hitting results for each value of the head physical properties; wherein

in the step of obtaining multiple pieces of measurement data and hitting results,

the multiple pieces of measurement data are obtained from swings of the golf players and hit balls of the swings, and

in the step of determining an indicator,

when the hitting results are made an objective variable, the characteristic value and values of the head physical properties are made an explanatory variable, and the characteristic value has a statistically significant relation with the hitting results, the characteristic value is determined as the indicator,

wherein

the hitting result is a right/left direction in which a ball flies;

the head physical property is a centroid position of a head, a lie angle, a bulge on the face surface or a moment of inertia of the head; and

the characteristic value is a face angle before impact or at impact.

19. The fitting method according to claim 7 , wherein in the relational expression 12, a preferred hitting result at a standard centroid position Gh of the head is reflected.

20. The fitting method according to claim 7 , wherein in the relational expression F12, more than two hitting results are considered.

21. The fitting method according to claim 7 , wherein the relational expression F1 is a linear expression.

22. The fitting method according to claim 13 , wherein

in the step of determining an indicator, a plurality of indicators is determined, and the method further comprising the steps of:

calculating an accuracy rate of values of head physical properties determined from the plurality of indicators; and

selecting an indicator to be used in fitting of a golf club, on the basis of the accuracy rate, wherein

in the step of calculating an accuracy rate of values of head physical properties,

a value Xa of the fit head physical property is selected based on a relational expression F1 of the indicator and the hitting results,

a value Xb of the fit head physical property is determined based on values of hitting results obtained from the swings, and

a golf player rate for which the value Xa and the value Xb match is calculated, and the rate is made an accuracy rate, and

in the step of selecting an indicator to be used in fitting of a golf club,

an indicator for which the accuracy rate is highest is selected to be an indicator to be used in fitting.

23. The fitting method according to claim 14 , wherein

in the step of determining an indicator, a plurality of indicators is determined, and the method further comprising the steps of:

calculating an accuracy rate of values of head physical properties determined from the plurality of indicators; and

selecting an indicator to be used in fitting of a golf club, on the basis of the accuracy rate, wherein

in the step of calculating an accuracy rate of values of head physical properties,

a value Xa of the fit head physical property is selected based on a relational expression F1 of the indicator and the hitting results,

a value Xb of the fit head physical property is determined based on values of hitting results obtained from the swings, and

a golf player rate for which the value Xa and the value Xb match is calculated, and the rate is made an accuracy rate, and

in the step of selecting an indicator to be used in fitting of a golf club,

an indicator for which the accuracy rate is highest is selected to be an indicator to be used in fitting.

24. The analysis method according to claim 18 , wherein

in the step of determining an indicator, a plurality of indicators is determined, and the method further comprising the steps of:

calculating an accuracy rate of values of head physical properties determined from the plurality of indicators; and

selecting an indicator to be used in fitting of a golf club, on the basis of the accuracy rate, wherein

in the step of calculating an accuracy rate of values of head physical properties,

a value Xa of the fit head physical property is selected based on a relational expression F1 of the indicator and the hitting results,

a value Xb of the fit head physical property is determined based on values of hitting results obtained from the swings, and

a golf player rate for which the value Xa and the value Xb match is calculated, and the rate is made an accuracy rate, and

in the step of selecting an indicator to be used in fitting of a golf club,

an indicator for which the accuracy rate is highest is selected to be an indicator to be used in fitting.