How is a bowler's average calculated?
For an example, Anil Kumble's test-match bowling average is 29.65. What does this number mean?
Let's take an example of Anil Kumble. He has taken 619 wickets and given 18355 runs in Test. So his bowling average = 18355 / 619 = 29.65.
The bowling average indicates the number of runs given by a bowler to take a wicket. So Anil Kumble gave 29.65 runs for every single wicket in Test.