says
Fair Play first
In the year 2021, an American academical guy made laboratory tests using several types of tennis rubber and several models of balls, in a climatical chamber with varying air humidity of 30-45-60-75-90%.
IMPOTRANT CONCLUSIONS:
--- when air humidity stay within 30-60%, the G40 ball has the best grip on the robbers of the 3 models in test.
-- when air humidity reached 70% or higher, all three ball models* clearly lost grip on the rubbers.
(*) The test balls were:
- Butterfly A 40
- Butterfly S 40
- Buttererfly G40
YOU SHOULD ALWAYS KNOW AS FOLLOWS.
Every playing court should have a psychrometer in a prominent place. Serious competitions are now disallowed from playing in high-humidity environment over 70% according to the Russian domestic Rules.
Be happy.
