The problem with this metric is it can be gamed. We had something similar, and there was a huge 'meta' over who gets the shiny new features, and who has to fix

The problem with this metric is it can be gamed. We had something similar, and there was a huge 'meta' over who gets the shiny new features, and who has to fix the legacy code which was like Jenga, and a single misstep could break thousands of tests, and writing code was like playing minesweeper. The people who won the 'meta', got to be the most productive. Thing is, probably the guy who fixed a bug in the legacy hairball by writing 10 lines of code produced tons of value for the organization (those unit tests weren't for show, they were customer use cases), while the other one only produced some, if the fancy new feature got adopted.