Is it possible to see the code on this?
Of course it is - see the file mod/workshop/eval/best/lib.php around the line no. 150 - the method
process_assessments() and other methods it uses such as
There are also unit tests for these, and it should not be hard to even produce some kind of charts and tables illustrating the behavior of the algorithm.
One of my long-term nice-to-have features for workshop is adding support for radar / spider charts that would display how one submission was assessed by multiple reviewers (one reviewer = one colored line around the web), each one assessing multiple criteria (each direction in the chart representing one criterion). It would then allow to show the hypothetical "best" (average) assessment and how the student's one is different from it.