It used some pretty interesting strategies around creating Git statistics such as the concept of seperating "new code" vs "churn". They defined churn as "modifying a line that had been previously modified in the last month" (I forgot if it was month or some other timeline).

It would chart if an engineer made a large number of "churn" diffs vs new code vs "legacy/refactoring" which was modifying code that was last touched a long time ago.