What is the right air pressure for U12 boys recreational soccer. If there is a right range why would one choose the lower or higher value?
USSF answer (September 10, 2008):
A good question, as the specifications for the balls other than for adult soccer are not included in the Laws of the Game.
Soccer balls for match use come in three different sizes, 3, 4 and 5. Size 3 balls are the smallest balls and are generally used for players under the age of 8; they are generally 23-24 inches in circumference and weigh between 11-12 ounces. Size 4 balls are generally used for players between the ages of 8 and 12; they weigh between 12-13 ounces and have a circumference of 25- 26 inches. The details on the ball for adult soccer (Size 5) are in Law 2 of the Laws of the Game. The composition and air pressure figures given in Law 2 apply to all the sizes. Only the weights and circumferences would differ for sizes 3 and 4.
The size ball used for U12 boys recreational soccer is up to the competition authority, the people who make the rules for the particular competition — league, cup or tournament. It would likely be a size 4.
The size 5 ball is spherical, made of leather or other suitable material, of a circumference of not more than 70 cm (28 ins) and not less than 68 cm (27 ins), not more than 450 g (16 oz) in weight and not less than 410 g (14 oz) at the start of the match, and of a pressure equal to 0.6 – 1.1 atmosphere (600 – 1100 g/cm2) at sea level (8.5 lbs/sq in 15.6 lbs/sq in).
Pressure figures are relative to the needs of the game. The air pressure to be chosen depends on weather and field conditions, the skill of the players, and, most practically and importantly, ensuring that the ball pressure is within the manufacturer’s specifications (which are often printed on the ball around the inflation point). A higher pressure usually makes a ball tighter and “faster,” in that it bounces higher and farther and requires much greater skill to control it. A lower pressure will soften the ball and slow it down.