One interesting topic surrounding the Cardinals' early success has been the discussion around their Run Differential.
As of Friday morning, it's actually a net ZERO on the season. St. Louis has allowed the same number of runs it has scored, yet the Cardinals are sitting seven games above .500.
So, we ask again, is it sustainable?
Well, look at how they're doing it. With a bullpen ERA of 4.77, Cardinals relievers rank 25th in MLB -- not great, is it?
However, when you realize the key relievers that see action when the Cardinals are leading by a small margin in the late innings -- George Soriano (3.31 ERA), JoJo Romero (3.50 ERA) and Riley O'Brien (2.00 ERA) aren't the ones harming that overall bullpen ERA, it stands to reason that the Cardinals can outperform both their run differential AND an overall lackluster bullpen ERA by just being great in the most important moments where the bullpen is needed to preserve potential wins.
And, they're doing that, evidenced by a superb 8-2 record in one-run games. The Cadinals are winning the close ones at a disproportionate rate, and Thursday night was a great example of that trend playing out.
The Cardinals got six strong innings from Matthew Liberatore before Soriano, Romero and O'Brien closed the door with three scoreless frames. That's the recipe to outperforming expectations and continuing to win more games than people think the Cardinals are supposed to win.
Can the Cardinals sustain it? If the key relievers we saw on Thursday in San Diego sustain what they're doing, absolutely.