St. Louis Cardinals: Don’t worry about Jack Flaherty’s 2020

Jack Flaherty had a down year in 2020 but heading into 2021, there is no reason to worry about the St. Louis Cardinals’ ace.

Coming into 2021, the St. Louis Cardinals have a large number of outcomes that they could get from their starting pitching staff. It could be great, but it could also be subpar. Barring another addition, the main four starters in the rotation will be set, with a competition for the fifth spot.

It’ll be great to see Adam Wainwright back yet again, but the entire rotation will be leaning on Jack Flaherty to lead the way. After his stellar second half of 2019, Flaherty cemented himself as No. 1 starter. In 2020 however, he took a step back.

Throwing 40.1 innings, Flaherty had an ERA just south of 5.00, a far cry from the 2.75 ERA he had in 2019. Looking at ERA+, he dropped from a 154 ERA+ to just 88. For a player that is supposed to be an ace, some are worried about if the 25-year-old is for real. I am here to tell you that 2020 should be thrown out of the window.

Digging in

To start, let’s state the obvious: 2020 was a messed up year. After getting ramped up twice (once for spring training and once for the 60-game season), the Cardinals had to deal with a 17-day COVID-19 layoff that included an extended stay stuck in hotel rooms. Flaherty wasn’t in the group that ended up testing positive for COVID-19, but each player deals with things a different way.

When the Cardinals finally started play again, the Cardinals were most-careful with Flaherty, keeping him on a pitch count. Because of this, Flaherty didn’t reach a pitch count over 83 until 5th start after the COVID layoff.

Looking at his Baseball Savant home page, the expected values were not good for Flaherty, but let’s dig a little deeper. After including the caveat of the stoppages and his limited pitch count, let’s look at what matters. In a small sample like 2020, the important thing to look at is whether or not Flaherty pitched in the same way as he did in 2019, even if the results didn’t work out.

We know that Flaherty’s 2019 plan works in a larger sample, so that is all we should worry about. Looking at his usage rates, nothing changed much between 2019 and 2020.

Primarily, Flaherty was the same fastball/slider pitcher that brought him the success he found in 2019. The next thing to look at is velocity. If Flaherty’s velocity dropped a lot, it could be an easy sign that something was off in his mechanics or that he was pitching injured.

Just like pitch usage, nothing really changed between 2019 and 2020. The other thing to look at is Flaherty’s ability to keep striking players out. From 2018-2020, Flaherty’s strikeout percentage went from 29.6% to 29.9% to 28.8% in 2020. He also remained elite with his 88th percentile whiff percentage. Again, nothing to worry about.

Another way to tell if Flaherty was really throwing differently is spin rates. If all of the sudden there was a drastic shift here, it would be another possible clue that he was injured or mechanically off. Looking at the chart above, his most used pitches (fastball and slider) didn’t change at all. His curveball dropped some but is still a healthy 2400 RPM.

If these usage and effectiveness values didn’t change, what did?

The biggest change for Flaherty from 2019 to 2020 was his walk rate. In 2020, his walked rate jumped up to 9.4%, more than 2% higher than his 7.1% walk rate in 2019. In a normal year, this could be a cause for concern, but in a year like 2020 where he had to stop and start so many times, it’s not surprising at all that Flaherty’s control never really hit stride.

Playing with sample size

The other aspect to look at here is sample size. As was mentioned earlier, Flaherty threw just 40.1 innings in 2020 over just nine starts. Included in those nine starts was one dud that, in a normal year, gets ironed out.

In Flaherty’s start on September 15 against the Brewers lasted just 3.0 innings, and by the end of his outing, he was tagged with nine earned runs. The smaller the sample, the more weight each start has.

If you take out that one start, Flaherty’s 4.91 ERA drops to 3.13. That is much closer to the ERA that we expect from Flaherty in a normal year.

With the absence of many other places to look for where and why Flaherty’s 2020 went wrong, this is where we enter 2021. Flaherty was still able to prove he could step up for a big game in the 2020 playoffs, so there is little reason to fret over a worse sample in 2020.

Flaherty has the drive to prove that last year was a farce and he’ll get plenty of chances. The Cardinals are counting on him and it seems that is exactly the spot Flaherty wants to be in. After digging in a little, here is little reason to believe that Flaherty won’t bounce back to the dominant pitcher he was in 2019 in 2021.