Why is clay slower than grass? Why does the ball bounce lower on grass courts? Learn about the differences between clay and grass.
Why is clay slower than grass? Why does the ball bounce lower on grass courts?
Players know these things are true, but technically, how can you be sure? We'll tell you.
There are several reasons for the differences between these two court surfaces:
• The coefficient of restitution of a ball: a ball falling from 1.8 m will bounce up about 1.3 m on a clay court and 1 m on a grass court.
• The coefficient of friction: a ball in play will lose 40% of its speed when it comes into contact with clay.
Because clay is more abrasive than grass, a ball moving at the same speed will lose just 30% of its speed on grass! Because grass is smooth, the ball slides more than it bounces.
On clay, the ball will stick to the surface for a bit longer, and so will gain more spin.
A serve at 190 km/h will bounce 8 km/h slower on clay than on grass. A player's reaction time on grass is 17% slower on the same serve.
• The regulation height of grass is 8 millimetres - no more, no less.
• The grass must be maintained year round for it to reach the right height when the season starts.
• There are just 6 natural grass courts in France.
• On 2 May 2007, for the first time ever, a hybrid court was built: half clay, half grass. It was created for an exhibition match between the world no.1 and no.2.
• The crushed limestone used for the courts at the French Open comes from a quarry in Saint Maximin in northern France. It is also used on many clay courts all over France.
Now you know the differences between clay and grass courts! And you've learnt some interesting facts! Brilliant!!