I bumped into this whitepaper from GitPrime while searching for "peter druecker software team". From what I understand, they analyze git commits to provide some insight on the developers productivity and performance.
While the idea look great, I'm not convinced it will help much in measuring team performance. Take for example a team of 3 developers, working on 1 issue for 3 days. They will brainstorm about the issue, do tests on production, write some scripts to reproduce the issue and then finally, maybe one of them will commit some code to fix it. So if you just looking at code as metrics, it mean only one developer is productive while the other 2 seem not doing anything in that period of 3 days.