
The Singles Game
3. The Ball
The ball shall have a uniform outer surface consisting of a fabric cover
and shall be white or yellow in color. If there are any seams they shall
be stitchless.
The ball shall conform to the requirements specified in Appendix I
(Regulations for making tests specified in Rule 3.) Section iv for size
and be more than two ounces (56.7 grams) and less than two and
one-sixteenth ounces (58.5 grams) in weight.
The ball shall have a bound of more than 53 inches (134.62cm.) and less
than 58 inches (147.32cm.) when dropped 100 inches (254.00cm.) upon a
concrete base.
The ball shall have a forward deformation of more than .220 of an inch
(.559cm.) and less than .290 of an inch (.737cm.) and a return deformation
of more than .315 of an inch (.800cm.) and less than .425 of an inch
(1.080cm.) at 18 lb. (8.165kg.) load. The two deformation figures shall be
the averages of three individual readings along three axes of the ball and
no two individual readings shall differ by more than .030 of an inch
(.076cm.) in each case.
For play above 4,000 feet (1219m.) in altitude above sea level, two
additional types of ball may be used. The first type is identical to those
described above except that the bound shall be more than 48 inches
(121.92cm.) and less than 53 inches (134.62cm.) and the ball shall have an
internal pressure that is greater than the external pressure. This type of
tennis ball is commonly known as a pressurized ball. The second type is
identical to those described above except that they shall have a bound of
more than 53 inches (134.62cm.) and less than 58 inches (147.32cm.) and
shall have an internal pressure that is approximately equal to the
external pressure and have been acclimatized for 60 days or more at the
altitude of the specific tournament. This type of tennis ball is commonly
known as a zero-pressure or non-pressurized ball.
All tests for bound, size and deformation shall be made in accordance
with the regulations in Appendix I.
The International Tennis Federation shall rule on the question of whether
any ball or prototype complies with the above specifications or is
otherwise approved, for play. Such ruling may be taken on its own
initiative, or upon application by any party with a bona fide interest
therein, including any player, equipment manufacturer or National
Association or members thereof. Such rulings and applications shall be
made in accordance with the applicable Review and Hearing Procedures of
the International Tennis Federation (see Appendix II).
ITF Note: Any ball to be used in a tournament which is played
under the Rules of Tennis must be named on the official ITF list of
approved balls issued by the International Tennis Federation.
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