If you trust fWAR's evaluation of relievers (I definitely hate WAR for relievers), then the Braves are -0.2 below replacement with an average pen right around 1.7. Two games is solid guesstimate.
I hate WAR for pitchers in general, and especially for relief pitchers. I find it to be a futile effort to approximate what our record would be. We have lost two games based on Fredi keeping Teheran in the 8th inning because he simply can't trust our bullpen. How do you measure strategy adjustments?
Or the aggregation impact of more pitchers needing to go on a daily basis because we can't get 3 damn outs per pitcher?