By The Numbers
Here we go with this numbers thing, again!
Our Racquet reviews are a bunch of numbers, but what do these numbers mean to you?
We have put together this table with a brief explanation of how each number can be used by you to understand how that property can be helpful.
If you see terms such as typical or normal, ignore them! With tennis players, there is no such thing as “typical and normal”!
If you need to be convinced, take a look at a previous post!
Please let us know if there is a number that needs more clarification or a number we are missing!
|Manufacturer||Yonex||What it Means|
|Racquet Model||Yonex VCore Pro 97 HD||Racquet being reviewed.|
|Reference Tension||55 lbs - 24.9 kg||Stringing machine tension setting. Not, necessarily, the string bed stiffness.|
|String||Ashaway MonoGut ZX Pro||String brand name and gauge (Pro being 17Gauge)|
|Machine Used||True Tension Professional||Stringing machine used.|
|ASPS, RDC||56||The stiffness of all the strings as a unit. Normally between 30 and 65.|
|ASPS, FlexFour||64.5||The stiffness of the string bed as tested on this device.|
|Racquet Flex, RDC||57 - After stringing||50 is low (flexible) and 70 is high (very stiff). Clash 100 is 52 on this device. As is a Head Speed model.|
|Racquet Flex, FlexFour||50||35 is low (flexible) 70 is high (very stiff). Clash 100 is 26 on this device.|
|Racquet - In Plane Stiffness||353.8 lbs/Inch||This is how stiff the racquet head is across the middle. 300 is soft and 500 is very stiff. This affects the string bed stiffness.|
|Weight, Grams||336||285 is light and 360 is heavy.
315 is minimum target weight for performance.
|Weight, Ounces||11.85||The racquet weight in ounces, typically used in US.|
|Balance, mm||322||This is the center of gravity from the butt cap. If you put the racquet on a round rod this would be how much is hanging toward the butt cap.|
|Balance, Inch||12.68||This is the CG in ounces for US. Points head heavy or head light is part of this.|
|Length, Cm||68.5||This is the total length of the racquet and is the typical standard adult length.|
|Length, Inch||26.968||This is length in inches for the US.|
|Head Width, Inches||9.57||The inside width of the hitting area.|
|Head Length, Inches||12.54||The inside length of the hitting area.|
|Head Area, cm2||625.8||The advertised hitting area in centimeters squared.|
|Head Area, Sq. Inch||97.0||The advertised hitting area in inches squared.|
|Number of Main Strings||18||The main strings are the vertical strings when looking at a standing racquet. Typically the longest strings.|
|Number of Cross Strings||20||The cross strings are the horizontal strings when looking at a standing
racquet. Typically shorter.
|Ratio Cross/Mains||.687||The natural ratio of the string pattern (calculated).|
|Main String Grid||7.25||The total distance between right and left main string.|
|Cross String Grid||10.18||The total distance between the first cross string and the last cross string.|
|Density (% of head filled with string)||.783|
|Average Cross String Space||.509||The higher this number the more the string will move. This number is used to help select the best string setup.|
|Average Main String Space||.403||The higher this number the more the string will move. This number is used to help select the best string setup.|
|Properties of a moving racquet.|
|Dynamic Tension, Kp, ERT||37||This is the stiffness of a string bed in kilograms per centimeter based on a frequency.|
|Dynamic Tension, Lbs/in||206.94||This is the above converted to pounds per inch.|
|First Moment, Nm||.831||This is how heavy the racquet feels in the hand. The higher the number the heavier the racquet will feel.|
|Polar Moment||340||This is the resistance to rotating about the center of the racquet on, say a mimes-hit. The higher the better.|
|Torsional Stability||16||This is the derived stability number. The higher the better within reason. Anything below 14 would need some help.|
|Swing Weight, Kg/cm2||324||This is the "inertia" of the racquet and probably the most important number in the review! The higher the number the more momentum through the ball but less manueverability.|
|Swing Weight, Ounces||11.43|
|Swing Weight Calculated||348.4||This number will be larger than the previous swing weight because it is calculated from the very end of the racquet as if there is no one holding it. A very important number.|
|Power, RDC||42||Calculated by the RDC. High is 100|
|Control, RDC||59||Calculated by the RDC. High is 100|
|Manueverability, RDC||71||Calculated by the RDC. High is 100|
|Power, Calculated||1740.5||This number is calculated based on a bunch racquet properties, Including length.|
|Head Points||6.46 (negative = head heavy)||This number is how positive or negative the balance is. A "point" is ⅛ of an inch so this racquet is a little over ¾ of an inch head light.|
|Head Weight, %||47.0%||Calculated based on weight distribution and length.|
|Center of Percussion||21.0||This is the spot on the string bed that returns a "solid" hit.|
|Dwell Time, ms||8.50||This is how long the ball and string are in contact with no swing. A big swing will reduce this number by about half.|
|Efective Stiffness - lbs||28.2||This number is calculated from the string bed stiffness and the racquet stiffness. Anything under 30 will be "soft" feeling and over 35 will be "harsh".|
|K, Lb/In||179.5||This is how many pounds it takes to deflect the string bed one (1) inch.|
|Recoil Weight||160.8||This number is the racquets resistance to rotating backward. The higher the number the better for volleys.|
|Twist Weight||230.8||This is the racquets resistance to twisting in your hand. The higher the better.|
|End Weight||139.8||This weight is used to calculate the precise balance of the racquet.|
|Tip Weight||196.2||This weight is used to calculate the precise balance of the racquet.|
|9 O'Clock||100.4||This is the weight of that position on the racquet head and is used for precise customization.|
|3 O'Clock||99.6||This is the weight of that position on the racquet head and is used for precise customization.|
|Butt Cap||135.6||This is the weight of that position on the racquet and is used for precise customization.|
Posted on February 7, 2020, in Customization!, Inspiration, Juniors, Learning, PEEK, Players, Racquet Demo, Racquets - New, String, String Patterns, Technology, Tension, Testing Devices, True Tension. Bookmark the permalink. Leave a comment.