The Cardinals Are Throwing Fewer Fastballs

16/04/2024 15:00

A number of Cardinals pitchers are trading fastballs for sliders in a sign that the Cardinals may be modernizing their pitching strategy.

Last year, about 11 months ago, I wrote an article titled "The Cardinals Throw Too Many Fastballs" (you can read that here). The premise of that piece was that in a league where fastball usage is declining, the St. Louis Cardinals haven't followed suit, throwing fastballs at nearly the same rate every single season. In fact, the team has finished with a fastball usage between 52% and 54% every season since 2018.

Over that time, league-wide fastball usage declined from 54.9% to 47.4%.

So what gives? Why is the league changing? And for our purposes, the question that matters is, why aren't the Cardinals changing with it?

To answer the former question, it's because the fastball is easiest pitch to hit. I think we know this intuitively. And I'm talking broadly here. Of course a hanging breaking ball over the heart of the plate is easier to hit than a 100 mph fastball at the top of the zone. That's not the point. The point is that, in general, hitters have an easier time hitting fastball than they do any other pitch type.

The numbers bear this out.

Last year, hitters had a wOBA of .348 against fastballs. Against all other pitch types, they put up a wOBA of .291. And therein lies the answer.

Pitchers are throwing fewer fastballs because fastballs are relatively easy to hit when compared to non-fastballs. A pitcher's goal is to get hitters out and non-fastballs give him a better chance of doing that than fastballs. It's a simple premise.

The argument here isn't for pitchers to stop throwing fastballs because of course there are plenty of scenarios where a fastball is the right call. Rather, the argument is for pitchers to stop throwing heaters at such a high rate.

This is an argument that I am sympathetic to and it appears the league is as well.

But the Cardinals aren't.

Or, at least they weren't. That seems to be changing this year. Whether it's a concerted effort to throw fewer fastballs team-wide or whether it's a sum of individual tweaks remains to be seen but either way, I take this as a positive sign that could very well mean the way the Cardinals think about pitching is getting more modern.

What I want to do in this article is take a look at some of the pitchers who are driving the change but before I do that we should stay at the macro level for a second. After sitting between 52% and 54% fastball usage for the past 6 seasons (and higher before that), the Cardinals fastball usage has dropped to just 47.2% this year.

That's just over the 47.1% league average but it also ranks 17th in the league, meaning that the Cardinals are on the right side of the median.

We could push past usage and get into results but I don't want to dive into results too much at a macro level for a couple of reasons. The first is that we're 16 games into the season and results can still change a lot (pitch usage can too which is why we aren't dealing in absolute fact yet. I'm banking that pitch usage, which can be a measure of overall pitching strategy, will have more staying power than results over a smaller sample.).

The second reason is because the Cardinals have a whole new pitching staff this year and that will likely have a larger impact on the numbers of the staff than a 6% decrease in fastball usage will.

So with all of this being said, let's dive into a micro level here. Which pitchers have seen the biggest decrease in their fastball usage? And what are the early returns of that change?

Here's a table of all Cardinals pitchers who have seen their fastball usages drop this year. (Note: Ryan Fernandez's 2023 fastball usage is from Triple-A)

Note that we have 9 pitchers here and of the 15 players that have thrown a pitch for the Cardinals this year, I only looked at 12 (Sonny Gray, Riley O'Brien, and John King were left out due to their incredibly small sample sizes). That's a rate of 75%. So at this point in this season, ³⁄₄ of the Cardinals pitching staff has dropped their fastball usages.

Small sample sizes are rife here but that's still a significant number.

What I want to do with the rest of this article is dive into some of the individual changes we've seen and see if we can identify why each pitcher is using his fastball less and how that change may help him.

Zack Thompson

I want to start with Zack Thompson because there's certainly some noise involved in his decreased fastball usage.

Zack Thompson's fastball usage may be down because he is legitimately trying to feature his secondaries, and especially his revamped changeup, more. Or it could be down because his velocity has lost 3 ticks. That makes it hard to analyze the changes he has made.

Still, he is leaning on his slider as his primary pitch against lefties and while his fastball is still his primary offering against righties, he's throwing his good changeup more than ever and also turning to his slider and his curveball.

If/when Thompson finds his velocity, he may start throwing his fastball more but I'm hoping that's not the case considering hitters hit it to the tune of a .369 wOBA last year.

Andrew Kittredge

The change Andrew Kittredge has made seems to be intentional. His velocity has not changed and there are no other factors that would seem to influence the change. Kittredge has always thrown his slider a lot but he's throwing it over 50% of the time for the first time since 2018.

So far this has been a positive change for Kittredge as he is getting a ton of whiffs and a ton of chases with the pitch early in the season. That's not to say his sinker isn't a good pitch, because it is, but sliders tend to be more effective than sinkers and Kittredge's ability to command the pitch both in the zone and out of the zone let's him throw it a ton.

Matthew Liberatore

I have been calling for Matthew Liberatore to throw fewer fastballs for at least 2 years and I'm overjoyed to see that he is finally doing so.

The lefty simply doesn't have enough velocity on his fastball to overcome its poor shape and because of that his fastball simply has never been effective at the major league level Yet despite that, the lefty's fastball usage has cleared 50% in each of his first 2 major league seasons.

This year that seems to be changing. He is throwing the pitch under 45% of the time and featuring his slider and a new cutter more.

I would still like to see him use his fastball even less but this is a step in the right direction and it's something I'll be monitoring as the season continues,

Giovanny Gallegos and Ryan Helsley

I'm grouping these two together because I see them similarly in terms of why they might be throwing fewer fastballs. The first reason is diminished velocity as Gallegos is down two ticks and Helsley is down one but the other reason is because both throw really good sliders.

In fact, both pitchers threw sliders with whiff rates over 50% last year and both have shown an ability to generate tremendous chase rates with their sliders. Those are pitches that can play as primary offerings and both righties have used them as such.

Miles Mikolas

After reading each entry in this list, you'll never guess which pitch Mikolas is featuring more.

It's his slider.

The pitch played as Mikolas most effective opf his four primary offerings last year in whiff rate, wOBA, and xwOBA and now, in response, he is using the pitch as his primary offering this year, getting thrown 31.6% of the time.

Final Thoughts

You should have noticed a few themes here. First, every pitcher who has pocketed his fastball a bit more has leaned on a pitch that was more effective for him in the past. That's a large part of why the league is shying away from fastballs and it seems to be a large part of why the Cardinals are seemingly starting to as well.

The other theme is increased slider usage.

After using sliders just 18.2% of the time, good for 26th in the majors, the Cardinals have used sliders 26.3% of the time this season. That's good for 5th in the majors.

That's quite a jump.

Some of that can be explained by who the Cardinals signed as Kyle Gibson, Sonny Gray, and Andrew Kittredge all feature sliders in their arsenals but it's also about how the Cardinals have traded fastball usage for slider usage from a number of pitchers this year.

In fact, it's that detail that makes me think this decreased fastball usage is intentional. The Cardinals seem to be leaning in on sliders specifically and they are doing it at the cost of fastballs. That's a positive change that should have a good effect.

Again, this could all be small sample size nonsense. I don't think it is based on some things I've seen in the minors (which I will write about at a later date) which make me think this is more of an organizational shift than a fluky sample size but it's still worth mentioning that possibility.

At the very least this is something encouraging that bears watching the rest of the season.

Thanks for reading.