The SiteScoreTM is a simple and easy indication of the quality of any group or cartridges or drives. It is based on the VeriScore® and it works just like it. A score of zero is very bad and a score of 100 is perfect.
It is however not just the average of the VeriScore® numbers.
Consider this example of two sites. Each site has two cartridges (they are small sites). Site one has a cartridge with a score of 100 and one with a score of 60. The average is (100+60)/2 = 80.
Site two has two cartridges with a score of 80 each. The average is of course 80.
So both sites have the same average quality score. However, we much prefer the second site. Its cartridges both have a respectable score of 80 and they are expected to perform well.
The first site has a cartridge with a perfect score of 100, which is nice. But the second cartridge has a problematic score of 60 and could cause problems.
Preferrably, the VeriScore numbers for all cartridges in a group are within a narrow range. Mathematically, this range is expressed by the standard deviation.