You might not have to go all the way back... I've thought of this concept before, and I think the key is to measure based on contributions to functional goals

You might not have to go all the way back... I've thought of this concept before, and I think the key is to measure based on contributions to functional goals of the project, not amount of code added. For example, participating in a discussion on requirements for a specific function is worth X points. Submitting the code is worth X points, too. Documentation is worth X points, as is communicating with the end users who requested the function or found the bug. In short, reward people based on participating in a collaborative development process. Then that 5-line patch is more highly rewarded by someone who takes ownership and truly participates, not just a random coder with time to spare. Might this discourage some people? Yes... but only people who wouldn't have time or inclination to be significant participants in the project anyway. In the long run, the team and project should be stronger. At least, I thi/hope so...