Issue link: http://itf.uberflip.com/i/428396
21 d. Only the ball types specified in the table below can be used in 10 and under tennis competition: Notes: 1 The deformation shall be the average of a single reading along each of three perpendicular axes. There is no limit on the difference between individual forward deformation readings. There is no specification for return deformation. 2 All coloured dots shall be reasonable in size and placement. e. All tests for rebound, mass, size, deformation and durability shall be made in accordance with the Regulations described in the current edition of ITF Approved Tennis Balls, Classified Surfaces & Recognised Courts. CLASSIFICATION OF COURT PACE The ITF test method used for determining the pace of a court surface is ITF CS 01/02 (ITF Court Pace Rating) as described in the ITF publication entitled "ITF guide to test methods for tennis court surfaces". Court surfaces which have an ITF Court Pace Rating of 0 to 29 shall be classified as being Category 1 (slow pace). Examples of court surface types which conform to this classification will include most clay courts and other types of unbound mineral surface. Court surfaces which have an ITF Court Pace Rating of 30 to 34 shall be classified as being Category 2 (medium-slow pace), while court surfaces with an ITF Court Pace Rating of 35 to 39 shall be classified as being Category 3 (medium pace). Examples of court surface types which conform to this classification will include most acrylic coated surfaces plus some carpet surfaces. Court surfaces with an ITF Court Pace Rating of 40 to 44 shall be classified as being Category 4 (medium-fast pace), while court surfaces which have an ITF Court Pace Rating of 45 or more shall be classified as being Category 5 (fast pace). Examples of court surface types which conform to this classification will include most natural grass, artificial grass and some carpet surfaces. STAGE 3 (RED) FOAM STAGE 3 (RED) STANDARD STAGE 2 (ORANGE) STANDARD STAGE 1 (GREEN) STANDARD MASS (WEIGHT) 25.0-43.0 grams (0.882-1.517 ounces) 36.0-49.0 grams (1.270-1.728 ounces) 36.0-46.9 grams (1.270-1.654 ounces) 47.0-51.5 grams (1.658-1.817 ounces) SIZE 8.00-9.00 cm (3.15-3.54 inches) 7.00-8.00 cm (2.76-3.15 inches) 6.00-6.86 cm (2.36-2.70 inches) 6.30-6.86 cm (2.48-2.70 inches) REBOUND 85-105 cm (33-41 inches) 90-105 cm (35-41 inches) 105-120 cm (41-47 inches) 120-135 cm (47-53 inches) FORWARD DEFORMATION 1 ------- ------- 1.40-1.65 cm (0.551-0.650 inches) 0.80-1.05 cm (0.315-0.413 inches) COLOUR 2 Any Red and Yellow, or Yellow with a Red dot Orange and Yellow, or Yellow with an Orange dot Yellow with a Green dot