Yesterday, the Royals made a big announcement. Kauffman Stadium, long one of the most cavernous venues in the majors, is going to be a little less warehouse-like this year. The walls are moving in nine or 10 feet more or less across the board, and getting shorter by a foot and a half to boot. That’s a meaningful change for a stadium where home runs generally go to die. How massive? Time to crank up the old computer and find out.

I plugged the new dimensions from Kansas City’s press release into an equation describing a rough arc. I fit those points to a cubic spline so that it could more closely resemble the actual stadium, with its pinched-in corners. I made a few approximations as well; for instance, the wall is moving to a height of eight and a half feet “in most places,” so I just applied that across the board. I also modeled the old dimensions the same way. That way, I had two different virtual walls built to compare some batted ball data against.

Notably, my approximation isn’t a perfect replica of the stadium. I don’t have a millimeter-scale, or even a yard-scale, map of the place. I can’t account for outfielders robbing home runs, which is definitely going to be more common with the lowered walls, though still quite rare overall. But by running it through both the old and new wall dimensions, I think that this unavoidable error can be minimized. It’s pretty clear that no balls that were home runs with the old outfield parameters will suddenly not be home runs with the new ones, so the thing we’re looking for is the difference, assuming that my approximation is close enough to reality. And it is: My modeling says that over the last three years respectively, 205, 162, and 159 batted balls hit in Kansas City should have turned into homers. In reality, it’s been 186, 147, and 151. Read the rest of this entry »

Here’s a weird chart:

If you’re like me, you’re struggling to make sense of it. The value of a barrel? But aren’t barrels a measure of value themselves? That’s like asking how many dollars a ten dollar bill is worth, or how you’d rate The Lion King on a scale of one to The Lion King. But that’s not actually how it works. Barrels are defined based on exit velocity and launch angle pairs that, according to the dataset MLB used in their creation, were extremely likely to result in extra-base hits. Those cutoffs have remained the same. The results on barrels haven’t.

What gives? Well, some of it is the ball, of course. I’m not breaking new news in the long-running ball aerodynamics debate; you can read some good recent entries into tracking drag coefficients and the like here and here. Indeed, if you’re measuring barrels that way, you can see a pretty straightforward decline. Here are home runs per barrel over the years:

Read the rest of this entry »

Earlier this week, I looked into the curious case of Benjamin Button. Er, no, that’s not right. I looked into the fact that the average age of big league hitters keeps declining, like Button, while pitchers haven’t followed suit. There are any number of possible explanations for that pattern, and if the mystery appeals to you, I highly suggest reading the comments of that article, where our excellent readers have advanced a number of solid theories. I think there’s plenty of meat left on the bone in figuring out what’s causing this trend, but I won’t be delving into that (much) today. Instead, I made like Woodward and Bernstein and followed the money.

Age is a decent proxy for service time; older players have generally, though not alway, been in the league longer than younger players. Similarly, service time is a decent proxy for salary; players who have been in the league longer generally make more money than newcomers, for a variety of reasons. So is our data really just saying pitcher salaries are going up? Well, kind of.

I took salaries for all major league players starting in 2019, discarding the abbreviated 2020 season. I split them up by type – pitchers in one bucket, hitters in another, and Shohei Ohtani in both. Total pitcher and hitter salaries have both gone up – passage of time, inflation, and so on. But after a huge increase heading into 2022, when seven different hitters signed nine-figure contracts, the total outlay to hitters has leveled off. Meanwhile, pitching salaries are catching up:

As an aside, I only pulled data through 2019 because it’s outrageously difficult to get complete salary data. If you’re looking for Opening Day annualized salaries, sure, those are reported. If you’re looking for free agency contracts, again, pretty easy to find. There are no disputes about what Freddie Freeman’s salary was in 2025; it’s public record. But what about Freeman’s former teammate Justin Dean, who racked up 52 days of service time in his debut season? What about split contracts? Late debuts? Up-and-down types? I worked out a method for what I consider a very good approximation of those salaries, but I don’t feel confident going back before the start of RosterResource’s database, which begins in 2019. Even then, this is approximate, though as I mentioned, I’m confident that it’s a good approximation. Read the rest of this entry »

I have a confession to make. I started this article with a conclusion in mind, only to find that that conclusion was spectacularly untrue. But then I pivoted, and found something else I think is quite interesting. Is it obvious, in retrospect? I kind of think so. But I had fun doing it and learned something in the process, so I decided to write about it anyway.

I had a theory that the average catcher age, along with the average age for all the hardest defensive positions, had plummeted over the past decade, with the average DH age increasing as a counterbalance. My theory was that the universal DH allowed teams to massively alter their behavior. National League teams that had been playing older sluggers in the field could shift them down the defensive spectrum, either directly to DH or by displacing other old players to DH via a chain reaction of moving to easier defensive spots.

It’s beautiful logic, with just one problem: It’s untrue. Here’s the average seasonal age (as of July 1 each year) of catchers, shortstops, and DHs since 2002, the first year we have positional splits that allowed me to run this analysis:

The data is pretty noisy, which makes sense to me. It’s not like teams are targeting a given age; they’re just making baseball decisions about cost, team control, and production. Average age is a downstream result of a lot of decisions that are made for other reasons. But in the aggregate, the pattern I hoped to see just wasn’t there:

In fact, DH has experienced the greatest decline in average age across all positions. That’s very much not what I expected. I do think that some of that is overstated. First base has had the smallest decline among positions, and I’d expect many of the displaced older hitters I mentioned in my hypothesis to end up there too. But if you average the age changes of first base and DH, they’re almost exactly the league average for position players. Clearly, the data do not support my claim. Read the rest of this entry »

Read the rest of this entry »

It’s not just the park. The A’s put on a power show in 2025, clobbering 219 homers, getting results up and down the lineup. Nick Kurtz led the way with a superlative rookie season, but he wasn’t alone; Brent Rooker socked 30 bombs, Lawrence Butler added 21 of his own, and Tyler Soderstrom split the difference with 25. Rooker and Butler signed extensions before the season. Kurtz is going to be around forever. Add Soderstrom to that group, too: Over the holidays, he and the A’s agreed to a seven-year, $86 million contract extension, as Jeff Passan first reported.

Soderstrom’s route to stardom is emblematic of this A’s team. He’s always hit well, but figuring out how to plug him into the lineup hasn’t been straightforward. Three years ago, he was a top 25 global prospect as a catcher. Huge, easy power combined with an ability to play the toughest position on the diamond were the selling points. But as he worked through the upper minors and debuted in Oakland, a clear weakness emerged: Soderstrom couldn’t actually catch all that well, and Shea Langeliers, another catching prospect, was an obstacle to everyday playing time behind the dish. After catching 123.2 big league innings that were both statistically and aesthetically ugly enough for the team to pull the plug, Soderstrom was left in search of a position.

In 2024, an early-season minor league stint to work on his defense combined with a mid-season injury meant Soderstrom barely played first base, the new position the A’s selected for him. But between drafting Kurtz and making Rooker a full-time DH, that position didn’t promise much long-term stability. Soderstrom went into 2025 trying to learn left field while also attempting to improve on a lackluster career batting line. A former catcher playing the outfield and maybe not even hitting well? His career was surely on thin ice. Read the rest of this entry »

‘Twas the week before Christmas, and all through Fenway, every fan was insistent: “Get a first baseman, today.” Or, well, probably not – why would there be fans at Fenway when there are no games, anyway? Why Christmas week in particular? Why did they construct their sentence awkwardly to suit a rhyme scheme? But forget about how hard it is to open an article – or at least how hard I’ve made it seem with this one. There’s a trade afoot! The Red Sox have acquired first baseman Willson Contreras from the Cardinals in exchange for right-handed starter Hunter Dobbins and righty pitching prospects Yhoiker Fajardo and Blake Aita, as Jeff Passan first reported.

In a free agent market awash in slugging first base/DH types, Contreras flew under the radar this offseason. Kyle Schwarber and Pete Alonso were the top names at the position, and both secured the deals befitting that status. The Red Sox were clearly interested in adding some offense, particularly in the infield, and were linked to both sluggers before they signed elsewhere. But there are more ways to improve your team than on the open market, and a pivot to Contreras soon followed. Read the rest of this entry »

The Phillies made the playoffs in 2025. The Royals nearly did, and certainly hope to play in October in 2026. Teams like that rarely line up on trades, what with both sides aiming to do the same thing and all. But rarely isn’t the same as never. Philadelphia and Kansas City found something they agree on other than their taste in Super Bowl matchups (last year’s every year, naturally), coming together on Friday to swap relievers: Matt Strahm is heading to Kansas City in exchange for Jonathan Bowlan, as Robert Murray first reported.

Trades are all about two teams with mismatched goals. Who would trade a superstar? A team that isn’t competing at the moment and isn’t one or two players away from changing that. Who would let go of a promising outfield prospect? A team that’s set in the outfield and light on the mound. This trade is two playoff contenders trading relievers, so most of those considerations don’t apply. But there’s still a mismatch in goals and resources here; you just have to look a little more closely.

The Phillies bullpen boasts an embarrassment of riches. Jhoan Duran, the closer, is one of the best in the business, a lockdown reliever you can set and forget in the ninth inning. José Alvarado missed most of the 2025 season thanks to a suspension and injury, but he’s an excellent late-inning option in his own right when available, and he should be back at full strength in the upcoming year. It doesn’t stop there; the team recently signed Brad Keller, who broke out as a dominant single-inning option in 2025. Even without Strahm, that’s a fearsome top trio of relievers, perhaps the best in the majors. Read the rest of this entry »

Is Luke Weaver good? I’m asking for a friend of mine who will remain anonymous, initials D.S. It’s a matter of some urgency, he told me. Perhaps – and I, of course, wouldn’t want to speculate – it might be related to a news item first reported by Will Sammon of The Athletic. Weaver and the New York Mets are in agreement on a two-year, $22 million deal that continues to overhaul their bullpen.

Eleven million a year for a quality reliever is a solid rate. Eleven million for a guy who is only a season removed from nearly carrying the Yankees to a World Series title? A screaming buy. Thus, the question in evaluating Weaver’s free agency is simple: Is he the guy who dominated in 2024, or the one whom Aaron Boone launched down the bullpen hierarchy and eventually gave up on in the 2025 postseason?

When the Weaver experience is firing on all cylinders, you watch him pitch and wonder why everyone can’t do it like this. He starts things off with a model-friendly four-seam fastball, 94-95 mph and with prototypical backspinning movement. The combination of velocity, movement, and command turn what might seem like an ordinary pitch into a great primary option. As a starter, Weaver’s fastball was plus but not unhittable. It was held back by subpar velocity, but that was the only shortcoming of an otherwise solid offering. His star turn in 2024 was driven largely by that pitch, with a few ticks of velocity making it a monster instead of merely good.

When Weaver isn’t pounding the strike zone with his fastball, he’s snapping off one of the best changeups in baseball. The superlative cambio has always been his top offering. He broke into the majors as a starter and used the change to survive, throwing it more than a quarter of the time without any other solid secondaries to speak of. It’s so good that it’s no mere platoon pitch, and it’s gotten better since his transition to the bullpen. The same few ticks of extra juice that turned his fastball unhittable also gave batters nightmares with his offspeed offerings. Read the rest of this entry »

Every year, FanGraphs (in this case, I am FanGraph) releases contract predictions for our top 50 free agents. We also run a contract crowdsourcing project for those players, and I have to say, the crowd is spectacularly good at this. Last year, for example, I looked through all of the various predictions across the internet and awarded the crowd the title of best overall prognosticator.

But honestly, the winner of that award was hard to determine because I didn’t have a great way to evaluate the various predictions. Why so difficult? Because not every deal ended up being for the length we all predicted. As an example, I predicted 12 years and $48 million per year for Juan Soto, while the crowd predicted 13 years and $45 million per year. Soto signed a deal that was for 15 years and $51 million per year. Who was closest to the mark? It’s not immediately clear. I did better on the AAV, but the crowd did better on the number of years. There’s no obvious determining factor to use when comparing the two. Even worse, the two are inversely correlated; more years generally means a lower AAV. The two predictions seem pretty similar to me, but I had to grade AAVs and total guarantees separately, and that just felt clunky and confusing.

After some time bouncing ideas off my friends and colleagues, and plenty of time in the FanGraphs Idea Generation Lab (not real, but man, it should be), I think I have a solution. It’s simple, really. Evaluating contract predictions would be much easier if the predictions and the actual contract were for the same length, so I made them all the same length. Read the rest of this entry »