There is no reason to expect that Jack Flaherty - based on his individual performance - will be anything short of excellent this season.
Even before his initial call-up, the KATOH system was projecting a median of 8+ WAR over Flaherty’s first six seasons, just based on his minor league numbers. With 2.3 WAR in 151 innings last year and a projected 2.8 WAR this season, he’s on pace to smash even those pretty optimistic expectations.
In the last ten years, he’s one of only ten 22-year-olds to pitch 150 or more innings with a below league-average FIP. Only six did so with a better FIP than Flaherty, and you’d recognize all of those names: Clayton Kershaw, Madison Bumgarner, Noah Syndergaard, etc. As Craig Edwards noted, Flaherty’s 13 K, 1 BB performance on my birthday last year was only matched by five other 22-year-olds in the last decade: Kershaw, MadBum, Jose Fernandez, Stephen Strasburg and Shelby Miller.
When you look at Jack Flaherty’s comps, you don’t see many “flukes.” You see absolute superstars and future Hall of Famers. There is no reason to doubt him, based on his individual performance. He was so good, in fact, that he’s being used in promo images for R.B.I. Baseball 19:
The ONLY reason you might doubt Jack Flaherty is that he is professional baseball pitcher, and as a group, they are one of the most unreliable and unpredictable sets of athletes you could find. They do something which is incredibly hard that gradually destroys their arm, the very tool they use to do their work. So, you know... take that into account.
By virtue of being a pitcher, Flaherty is something of an injury risk, but he doesn’t have a particularly alarming history of injuries. Even though the “Verducci Effect” has been largely debunked, if you buy into that sort of thing, Flaherty only threw 10 more innings in 2018 than 2017.
What about the good ol’ sophomore slump? That seems even harder to quantify, but beyond whatever part of that is just injury risk, I suppose it mostly has to do with the league making adjustments against you. And yeah, I suppose that could happen. But I’d wager Flaherty is more insulated against that than most, on account of his repertoire being sick, as well as filthy and wicked.
Those are the factors I would suggest you take into account as you predict La Flama’s stats in the form below. To summarize my own feelings: I expect him to be super good.