He wouldn't have a good explanation, and he would often imply that baseball seasons can be quirky. To make his case, he'd bring up the 2009 season, when he was .500 at home (7-7), but 12-1 on the road.
Here's the thing. Even in that instance of 2009, Wainwright's ERA was still way better at home (a minuscule 2.05, in fact), compared to the road (3.39).
This is all pertinent as news broke Tuesday that Wainwright, age 38, signed a one-year deal to return to the Cardinals for 2020. It's a smart signing for numerous reasons.