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Jack Flaherty has been the best pitcher in the NL in the 2nd half

Yep, he’s been that good.

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St Louis Cardinals v Los Angeles Dodgers Photo by Jayne Kamin-Oncea/Getty Images

Jack Flaherty had an exceptional rookie season, and expectations were high for 2019. Peter Gammons even pegged the 23-year-old, in his first full MLB season, as his favorite to win the Cy Young Award.

Like every member of the Cardinals rotation, Flaherty spent a good part of the early season underperforming. Up to the All-Star break, he had 18 starts and had yielded 20 home runs. His ERA sat at 4.64. He was... fine, but nobody’s idea of an All-Star or certainly not a Cy Young contender.

Since the All-Star break, Jack Flaherty has been the best pitcher in the National League.

Here’s where Flaherty ranks among all qualified NL Starters in a few key categories since the All-Star break: WAR (1), ERA (2), FIP (2), K% (2). His ERA- for the 2nd half has been 16, meaning he has been 84% better than the average starter.

Care for some more #erotic Jack Flaherty stats?

Craig’s piece gets a bit more into the nitty-gritty of what’s making Flaherty more effective, particularly the way he’s using his slider against both righties and lefties. (You should always read Craig.)

I’m just here to join the chorus of Cardinals watchers who are noticing that SOMETHING IS HAPPENING. Early season performance tends to cement itself into the narrative. We are collectively slow to notice big turnarounds that happen midseason. And this, folks, is a big turnaround:

via Fangraphs

Are there reasons to believe this is a fluke? It’s only six starts, so of course it’s a small sample size. But the underlying numbers are legit. Whereas his HR rate was a bit flukishly inflated in the first half, it’s a bit flukishly deflated in the 2nd half. But he still sits at 7th in xFIP, which adjusts HR/FB to league average, so that’s nothing outrageous.

As you can see from the chart, Flaherty’s ERA and FIP have tracked each other pretty well throughout the season. His results have generally matched his performance, and his performance of late has been very, very good.

The ship has sailed on Peter Gammons’ Cy Young prediction for this season, but this run of success has Flaherty rocketing up the leaderboards in all of these categories. It won’t be enough to catch the likes of Scherzer, de Grom or Ryu this season, but Flaherty is setting a baseline that is absolutely in that league.

What Jack Flaherty means to the Cardinals and their playoff hopes is even more important.

One problem that has dogged the team over their recent run of non-playoff seasons is an abundance of average talent, but a dearth of elite talent, on either the hitting or pitching side. Flaherty’s excellent rookie campaign, and the Cy Young calibre 2nd half he is putting together, makes a strong case that he could be the ace of the staff the Cardinals have been looking for.