Cricket: A new bowler’s average
by Murray Woodman on Aug.27, 2009, under Know Idea
As I was watching the recently completed Ashes series this year I began to ponder the issue of how a bowler’s average is calculated. Is the current a bowlers average the only measure we can use? How can we accommodate the quality of the batsmen dismissed. I think that the current method could be augmented so that we have a more insightful way of discriminating between bowlers.
For those of you who aren’t familiar with cricket a bowler’s average is calculated by dividing the number of runs scored against the bowler by the number of wickets taken. If a bowler has the amazingly good average of 20 it means that they take a wicket every 20 runs.
One problem with this metric is that the quality of the batsmen dismissed will vary. Some bowlers will have tidied up the tail end batsmen more often. Others might be adept at getting out the upper order. How do we distinguish between these two? The solution is to deduct the averages of the batsmen dismissed from the average before dividing by the overs bowled. I call this measure “Bowler’s contribution”
Bowler’s contribution = (bowlers average – average of batsmen’s averages) / overs bowled
The outcome is that you have a measurement which takes into consideration all relevant factors:
- number of wickets taken
- number of runs conceeded
- quality of batsmen dismissed
- number of overs bowled
So, lets take four bowlers:
| Bowler | Average | Bats average | Contribution |
|---|---|---|---|
| Alfie | 20 | 40 | 20 |
| Bertie | 20 | 20 | 0 |
| Charlie | 30 | 40 | 10 |
| Davie | 30 | 20 | -10 |
Using the traditional method the best bowlers here would be Alfie and Bertie. However, the “contribution” method scored Alfie and Charlie the best because they are dismissing batsmen of a higher calibre.
This new method does have practical problems associated with it because it requires that the statistician know all of the batsmen’s averages for each innings they play. This is not the kind of statistic you will necessarily find in a book but it shouldn’t be too difficult to calculate if you have a comprehensive historical record.
So there you have it. It would be very interesting to see how bowlers would line up using this method. I reckon it would uncover a few unappreciated gems. Something more for the commentators to talk about. Cricket fans… what do you think? Let me know in the comments who the best all time bowlers would be on this new criteria.
