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Breaking Down Offseason Targets - Sonny Gray

Sonny Gray may never replicate his 2023 season but he’s still a fine arm.

Division Series - Houston Astros v Minnesota Twins - Game Three Photo by David Berding/Getty Images

Next up in my offseason targets breakdown series is the pitcher I think the St. Louis Cardinals are most likely to sign - Sonny Gray. As the oldest, and, perhaps, the least talented member of the big 3 free agent pitchers (Gray, Snell, Nola), Gray will likely command the contract with the fewest number of years attached and the least amount of dollars overall.

That makes him a prime candidate, for better or for worse, for a team that needs to fill out 3 rotation spots and needs at least 2, though I would prefer 3, of those arms to be better than Miles Mikolas.

Something else that works in the Cardinals favor is Sonny Gray’s preferences. He has said that he wants to be closer to his family in Nashville and that this decision isn’t all about money for him.

Taking a quick glance at Google Maps, Nashville is 4 12 hours away from St. Louis, which makes St. Louis about 8 hours closer to Nashville than Minneapolis, where Gray currently plays. That makes the Cardinals and Gray a strong match while the financial aspect of a potential deal only makes the pair a stronger match.

So, again, this is the pitcher I expect the Cardinals to sign, and I wouldn’t be shocked if they reached a deal pretty early in the offseason as the Cardinals will likely try to lock up at least one higher end starter early.

So while everything fits on paper, we still need to figure out just how good Sonny Gray really is. That’s the purpose of this piece.

If you want to read my earlier breakdown of Blake Snell, you can read it here. Otherwise, let’s dive in.


There are a lot of things that can be said about Sonny Gray, and I’ll get into them in this article, but there’s something I want to point out first. He’s been remarkably consistent in recent years. Yes, his ERA and fWAR have fluctuated from year to year but take a look at his xFIP to see what I mean:

2019 - 3.65

2020 - 3.19

2021- 3.66

2022 - 3.66

2023 - 3.65

That’s pretty incredible, quite frankly. For the last 4 full seasons, Gray has pretty much been the exact same guy, at least in terms of xFIP.

So, the logical conclusion is that he is who he is, right? I mean, you know what you’re going to get with Sonny Gray - a 3.65 or 3.66 xFIP. So, should we expect another season of a 3.65-3.66 xFIP in 2024? I would argue probably not.

Gray will be 34 entering next season and we know that past performance isn’t a predictor of future success.

While it is great to see that Gray’s remarkable consistency from age 29 to 33, the Cardinals, or whichever team ends up signing Sonny Gray, aren’t paying for his age 29-33 seasons. Those are done. So while it’s a great sign that Gray hasn’t shown the effects of age yet, we still need to examine what he may look like going forward.

Surface Level Analysis

Let’s stay on the surface first and just take a look at Gray’s Fangraphs page.

There are a few things that jump out immediately. The first is that Sonny Gray was really good this year. His 5.3 fWAR is not only the best single season total of his career but it’s also the 4th best among MLB pitchers this season while Gay’s 2.83 FIP is also tops in the league among qualified arms. The soon-to-be 34-year-old could easily end up with the AL Cy Young this year and nobody would bat an eye. He’s been that good.\

So that’s the first thing that jumps out at me. The second is that there’s a big gap between Gray’s actual numbers and his expected numbers. That’s not necessarily a bad thing as his expected numbers are still quite good, but expecting Gray to repeat a 2.79 ERA or 2.83 FIP next year would be foolish.

The gap in expected numbers appears to be due in part to some fortunate home run suppression in favor of the right-hander. Among qualified pitchers, Gray’s 0.39 HR/9 finished best in the league. The next best was Justin Steele at 0.73, nearly double Gray’s home run rate.

And while keeping the ball in the yard is a good thing, and Gray has typically been good at that throughout his career, it’s clear that the righty benefited from some good fortune this year. His HR/FB% was a league leading 5.2%, which was more than 3% better than the next best pitcher (Justin Verlander at 8.5%). The league average this year was 12.7%. Sonny Gray’s career average, which is pulled down a bit by this year, is 11.5%.

Generally speaking, a pitcher’s HR/FB% tends to stay near the league average. This is why xFIP is important. xFIP normalizes the home run component of FIP by adjusting a pitcher’s home run total to his expected home run total based on the amount of fly balls he surrendered and the league average HR/FB%.

Since HR/FB% isn’t sticky and can fluctuate by a decent amount year-to-year, this gives us a way to normalize, adjust and compare FIPs of different pitchers.

So, basically, my point is that while Gray had a fantastic season, he hit his 95th percentile outcome, or maybe even his 99th percentile outcome. Much of the extreme success of his year was due to some...let’s say...fortunate home run suppression that shouldn’t be expected to continue.

This means that we shouldn’t necessarily evaluate Gray using fWAR, which primarily uses FIP, with some adjustments, to evaluate pitchers. Gray certainly had a great season but 5.3 fWAR is simply not sustainable year over year.

Can he hit 3 fWAR, and maybe even 4? Sure. It’s possible. In fact, I would expect him to settle into the 3ish range at the beginning of his new contract. But that begs the question, is this the top of the rotation arm that the Cardinals want?

A 3 WAR pitcher is fine and good, even, but I want the Cardinals to aim higher. So if the Cardinals do bring in Gray, they can’t just pack it up and call it good. They need to grab a higher upside arm too.

Pitch Level Data

Let’s not stop our analysis there, though. Pitch level data is important. If a pitcher’s velocity is showing signs of decline, then we should adjust our expectations. If a pitcher recently learned a new pitch that helped him have a better than expected year, we should adjust our expectations. And, going beyond expectations, it’s important to understand what makes a pitcher successful to help determine how well he might age.

So what does pitch level data tell us about Sonny Gray? It tells us that he has a wipeout sweeper and a balanced arsenal.

In fact, it wouldn’t be a stretch to call Gray’s sweeper on of the best pitches in baseball this year as it allowed just a .114 wOBA and a .164 xwOBA, while getting whiffs on 41.3% of the swings that it induced. That’s just nasty.

Beyond that, though, there are two things that I find particularly interesting about the pitch. The first is that Gray hardened it up this year, throwing it nearly 3 mph harder than he did last year. That took what was already a good pitch and made it one of the best pitches in the league.

That’s pretty easy to understand though. There’s a correlation between velocity and stuff+ and while most people probably think of velocity in connection with fastball, it’s the breaking stuff that generally gets a lot nastier when it’s thrown harder.

This explains why Gray’s sweeper saw its stuff+ tick up from 111 last year to 121 this year.

But there’s more. Not only did Gray’s sweeper get nastier but he used it differently too.

In 2022, Gray threw 192 sweepers (10.3% usage), and all but 5 of them were thrown to right-handers. Intuitively, this makes sense as sweepers tend to have heavy platoon splits so pitchers typically use them to neutralize same-sided hitters.

This year, though, not only did the right-hander throw his sweeper more but he also started throwing his sweeper to opposite handed batters more. The interesting thing is that it worked. Gray increased his sweeper usage to 20.4%, making it his second most used pitch, and, of the 576 sweepers that he threw, 34.4% of them were thrown to opposite-handed batters. For comparison’s sake, that rate was just 2.6% last year.

Against same sided hitters (righties), the pitch allowed a .117 wOBA and that fell to just .110 when thrown to opposite handed batters (lefties).

This is big for Gray because it means that he was able to drop his curveball usage from 24.6% to 16.9% and replace it with sweeper usage. I’m not saying his curveball is bad by any means but it’s not nearly as effective as his sweeper.

Sonny Gray’s Breaking Balls

Pitch Usage% wOBA xwOBA Whiff%
Pitch Usage% wOBA xwOBA Whiff%
Sweeper 20.4 0.114 0.164 41.3
Curveball 16.9 0.295 0.320 28.2

The benefit of the pitch is that curveballs tend to be more effective than sweepers when a pitcher is at a platoon disadvantage. If Gray’s sweeper proves to lean platoon neutral then he gets the benefit of throwing his better breaking ball more often. I’m not quite ready to say that trend will continue though. It’s interesting to see Gray’s sweeper demolishing lefties this year but I’ll need to see that happen over a larger sample size before I’m ready to accept that the pitch is an exception.

So that’s another reason to think that Gray won’t be as effective next year. I could be wrong and his sweeper could keep eating lefties alive but, regardless, I would expect the pitch to not be as effective as it was this year. And that’s not necessarily a slight on Gray, either. The pitch was simply crazy good this year, to a point where it’s hard to imagine the pitch settling in at that level of production.

I’m not going to say much about Gray’s fastballs since both his sinker and his four-seamer are pretty pedestrian, sitting 93 without exciting shape with both pitches getting hit relatively well (.352 wOBA vs. 4-seam, .359 wOBA vs sinker). What I will say is that diminshed velocity is often an early sign of decline for a pitcher and Gray’s velocity has not diminshed one bit. In fact, his fastball velocity this year was higher than each of the previous two seasons and is only about 12 mph lower than when Gray was in his prime in his mid-to-late 20s.

That’s a good sign. If his fastball velocity has already started declining, I would have no interest in paying the price for him this winter.

The other good sign is that Gray has a pretty balanced arsenal, with 5 pitches seeing double digit usage and no pitch seeing more than 27.2% usage. Gray has never been a particualrly fastball heavy pitcher but he has backed off his fastball usage in recent years, and this year used his sinker and his four-seamer a combined 42.9% of the time.

Someone who uses a lot of secondary stuff, locates all of his secondaries effectively (as Gray does), has a go-to breaking ball, and mixes all his pitches feels like a good bet to age pretty well. Gray checks all of those boxes. So, while I don’t think he’ll come close to another 5 WAR season, I don’t think he’s just going to fall off a cliff any time soon. He should still be an effective pitcher for at least a few more seasons.


Sonny Gray had a career year in 2023 and the Cardinals shouldn’t be willing to pay a soon-to-be 34-year-old a premium because of that. And I don’t think they will. The market will have the same reservations about Gray as the Cardinals. His excellent season may have increased his value but I don’t think it skyrocketed it.

If the Cardinals want to pursue Gray as the second or third best starter they sign this winter, I’m fine with it. He’ll be the cheapest of the big 3 domestic free agents and sign the shortest contract. Basically, he’s the discount option of the high end pitching market this winter. Pair that with his location preferences and there are a lot of reasons to expect that he will be a Cardinals in 2024.

If the Cardinals do sign him, I won’t be in love with the signing but he would undoubtedly make the rotation better. Even if he won’t contend for another Cy Young, he can still be an effective arm for another couple of seasons at least.

At long as he isn’t the best pitcher the Cardinals sign, I’ll be content with the move and excited for what it means for a pitching staff that desperately needs talent.

Thanks for reading, VEB. Have a great Sunday.