[That Guy]

I don't know if anyone's done any real science on the value chart. Someone made one up and everyone's just kind of been going by it ever since (the good enough or "seems right" principal).

It wouldn't be easy to regression test either (only track rookie contract? games played? games started? bonuses for superbowl/pro bowls? value for general right of refusal on 2nd contract? how do you account for injuries or performance metrics (or do you bother?))

Just saying, the chart isn't perfect or set in stone.