So apparently the NFL has integrated something into the salary cap formula that gives team an incentive to keep veteran players. Only a fraction of their base salary counts against the cap, in this case only about 56%. I wasn't aware of this, but it makes re-signing Fabini even more sensible. Clipped this from PFT:
Fabini gets a one-year deal worth a total of $870,000 to him but costing only $485,000 to the Redskins in real dollars and cap dollars, thanks to the procedure for encouraging teams to choose veterans over younger guys who come much cheaper.