The December 20, 2025 FanGraphs Weekly Mailbag landed at just the right time for baseball obsessives. It arrived right after the post–Winter Meetings transaction blitz, but before the dust settled on the biggest free-agent signings.
This week’s mailbag leans into the chaos, using a flurry of deals—from the Padres doubling down on their rotation to the Orioles betting big on upside—to spark a bigger conversation. Roster construction, undervalued stars, and how we even think about pitching stats are all in play. No wonder the FanGraphs mailbag keeps serious fans coming back.
A Post–Winter Meetings Flurry Reshapes Contenders
The weeks after the Winter Meetings often show which front offices are bold and which ones play it safe. This year, teams used December’s second wave of deals to patch holes, take some gambles, and in a few cases, completely rewrite their plans.
Padres Double Down with Michael King and Sung‑mun Song
The San Diego Padres aren’t slowing down. First, they re-signed Michael King, a move that gives their pitching staff some much-needed stability.
King’s ability to start or pitch multiple innings out of the bullpen gives San Diego the kind of flexibility you want over a long season. Later, they dipped into the Korean talent pool and added infielder Sung‑mun Song.
Song isn’t a household name, but the Padres clearly like his contact skills, defensive versatility, and the fact that he’s cost-controlled. For a team with budget limits but big ambitions, that’s a smart blend.
Twins Add Middle-of-the-Order Thump with Josh Bell
The Minnesota Twins made their own statement by signing Josh Bell to anchor the lineup. Minnesota’s offense has always been streaky, living and dying by power surges and slumps.
Bell isn’t going to carry the whole offense, but as a switch-hitter who can work counts and drive the ball from both sides, he gives the Twins a real run producer. In an AL Central where “least flawed” sometimes wins, even small upgrades matter.
Phillies Swap Corner Outfield Power with Adolis García
The Philadelphia Phillies went aggressive and grabbed Adolis García as a functional replacement for Nick Castellanos. García brings better defense, more athleticism, and serious power, even if his OBP can be streaky.
Castellanos is still on the roster for now, but most expect him to get moved before Opening Day. Until then, the Phillies have some overlap in the corners, but the message is pretty clear: they want more two-way impact from their outfield, not just extra-base hits.
Michael Baumann, in classic FanGraphs style, compared teams’ offseason moves to babies putting everything in their mouths. It’s a vivid image for this stage of the winter, where clubs just want to see what sticks.
Rays, Orioles, Pirates, and Astros Shake Up the Trade Market
The trade market heated up fast, especially in the AL East. The Rays, no surprise, were right in the middle of it.
Shane Baz Heads to Baltimore in a High-Upside Play
The big move was a Rays–Orioles trade sending Shane Baz to Baltimore. This is exactly the kind of swing a contender with a deep farm system should take—betting on elite upside where it matters most.
Baz comes with risk—health, workload, command—but the raw stuff is frontline. The Orioles have loaded up on bats for years and now need arms, so this is a bold move while their window is wide open.
A Three-Team Puzzle: Rays, Pirates, Astros Get Creative
Another big story was a three-team trade connecting the Rays, Pirates, and Astros. FanGraphs even broke it down in a separate staff piece, because these deals get complicated fast in today’s era of tight budgets and sharp front offices.
These trades usually have a few goals:
Creativity ties it all together—the same thing Baumann joked about with his “baby with everything in its mouth” analogy.
Top Free Agents Still Waiting, “Matrix Reloaded” on Deck
Even with all this action, several top free agents are still waiting. Four of the top five players from Ben Clemens’ Top 50 list haven’t signed yet, which means the 2026 season’s true shape is very much up in the air.
Instead of digging into those big names in the mailbag, FanGraphs is handing that off to Jon Becker’s “Matrix Reloaded” column. That’s where the fit, projections, and the big-picture math get sorted out. The mailbag keeps things nuanced and curious, while the matrix column tackles the hard numbers.
Inside the Mailbag: WAR, WPA, and the Windup
With the rumor mill humming, this week’s mailbag dove into some deeper questions for the analytically curious. Instead of contract talk, the focus turned to how we actually evaluate players and strategies.
High-WAR Position Players Who Never Made an All-Star Team
One thread looked at high-WAR position players who never made an All-Star team. Statheads love this stuff because it shows the gap between reputation and real value.
FanGraphs WAR can dig up players who quietly delivered elite value—on defense, on the bases, or just getting on base—without ever grabbing headlines or All-Star nods.
These players usually have a few things in common:
All-Star picks are part performance, part popularity contest, and rarely a perfect measure of value.
Why WPA Beats Pitcher Wins in Modern Analysis
Another question asked about Win Probability Added (WPA) versus old-school pitcher wins. The logic is simple: WPA tracks how much a player’s actions swing his team’s chances of winning in real time, while pitcher wins just reward whoever’s on the mound when the offense wakes up.
In today’s analysis, WPA gets the love because it:
Pitcher wins flatten nuance, while WPA digs in and highlights the real impact—especially with bullpen arms and late-inning guys.
Rethinking the Windup and Pitching Mechanics
The mailbag also poked at the mechanics of the windup versus the stretch. With today’s game focused on tempo, control, and shutting down the run game, some pitchers just feel better working mostly from the stretch.
The windup, once standard, now comes down to personal preference. For plenty of pitchers, the stretch offers:
It’s part of a bigger trend: teams and pitchers are questioning every old habit, from delivery style to pitch mix, searching for any edge they can find.
FanGraphs Membership: The Gate to the Mailbag
FanGraphs keeps the mailbag as a Members-only perk. It’s both a thank-you and, honestly, a bit of a nudge.
Membership opens the door to these in-depth Q&As. It also helps keep independent, data-driven stories coming, which—let’s be real—makes the offseason chatter a lot more interesting.
Readers can send in questions for future mailbags. The best ones usually lead to the kind of detailed, thoughtful analysis that sets a FanGraphs mailbag apart from the usual inbox noise.
With so many rumors flying around every winter, having that level of rigor feels pretty valuable—maybe even more than some free-agent signings.
Here is the source article for this story: FanGraphs Weekly Mailbag: December 20, 2025
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