DO MOUND VISITS HELP?
> I went back to every Cardinals game this year in an attempt to estimate how much mound visits actually help pitchers. Below is how Cardinals pitchers did in an inning before and after a visit by the pitching coach, how their opponents did then and the combination of both. “PA” stands for plate appearances, but sac bunts and intentional walks were not factored in.
First the Cardinals (season .676 OPS allowed, 20% K, 8% BB):
Their opponents (MLB non-Cardinals .703 OPS allowed, 20% K, 8% BB):
Total (.703 OPS, 20% K, 8% BB):
It’s hard to be sure about how much pitching coaches help since they usually only visit in the first place because the pitcher couldn’t do any worse. Even so, the chaos does stop and on average pitchers not only do better than they were in the inning, but better than they do by themselves in any inning.