I don't think Lance Lynn has a first-inning problem. He might be fatigued, but it's hard to say. And I don't think he's particularly likely or unlikely to come through in a big game, like the one he started by accident on Thursday, relative to anybody else with his skills.
I'm starting there, with my boring sabermetric-orthodoxy fun-killing spreadsheet-thoughts, because I don't think any of that diminishes the importance of Thursday night's win, or ought to. That Lynn probably doesn't have some special skill that makes him heroic and lights-out under pressure—just like he probably doesn't have some fatal flaw that makes him flakey and unreliable—only makes it a more heroic performance, to me.
I think the idea that saber-oriented fans don't actually like watching baseball—don't have the same emotional connection to it as other fans—comes from the understandable, incorrect assumption that all baseball fandom is operating on the same time horizon.
For some people, it's enough to know that Lance Lynn has been bad in the last month and was good yesterday, and to build out from there the idea that he was unprepared to be in the rotation then and is prepared, again, now.
That's got a nice story arc, and the protagonist comes to a moral realization and figures things out just in time. To say he probably wasn't so bad in August, really, leaves you with the sabermetric caricature: Everything is luck, nothing is really worth watching.
Until you pull the camera back. I think it's self-evident that individual games are determined by a lot of things that we can't suss out as totally luck or skill, and that big games are no exception—but as part of a larger season, or even a larger career, they can offer that same catharsis they did back when you thought you'd never say anything as dumb-sounding as "BABIP" out loud.
If you thought Lance Lynn was completely adrift and has now righted things, that's great; but I'm getting the same mileage, this morning, out of remembering that a pitcher who was set to be the Cardinals' top Mitchell Boggs-shaped setup man back in February picked up his 15th win in September, at the exact moment the team needed it.
That some of the difference between Lynn at his best and Lynn at his worst can be found hiding in fly balls that would have been out of other ballparks or ground balls that found Daniel Descalso's glove instead of the space where Ryan Jackson might have been is ultimately irrelevant; Lynn's been pitching like this all year—putting himself and the Cardinals into position, again and again, to earn a little good luck.