There is a report in the March edition of the Wisden Cricketer on the development of a wicketkeeping ranking system. Developed by Adam Crosthwaite, a wicketkeeper for New South Wales, it is modelled on the baseball system, calculating the percentage of chances taken of those offered, and expressing the result as a decimal.
The thrust of the system and the report is sound: a wicketkeeper should be judged not by how many chances he takes, but by how many he misses. I had no reason to become agitated until I read the final paragraph, which begins thus:
"We may never know if Alan Knott rated higher than Rod Marsh..."
I can be of assistance here.
Alan Knott was a far better wicketkeeper than Rod Marsh, and any system that concluded otherwise would not be worth the numbers it crunched.