Baseball has gotten younger and more athletic, with a priority placed on those who can play valuable up-the-middle spots. This is part of why it’s harder than ever to find a hit, and it’s definitely correlated to who gets the biggest contracts in free agency. Youth is king.

We start with that because we’re keenly aware of how this is going to sound: One of the most interesting free agents of the winter is a first baseman who is going to be 34 before Opening Day. Let’s talk about Christian Walker, the best position player that you probably don’t know much about – and why, for some (not all) teams, he might not just be an alternative to Pete Alonso, the biggest first-base name available. He might be preferred.

Walker just put up three very similar seasons at the plate for Arizona, which is to say “OPS+ of 125, 122, and 121, with homer totals of 36, 33, and 26.” That’s a top-50 bat, as valuable or better than names like J.D. Martinez, Matt Chapman, or Bo Bichette. In fact: It might stun you to realize how similar his 2022-24 production with the bat has been to Alonso’s, his main competitor this winter.

• Walker: .250/.332/.481, 123 OPS+, 21% K
• Alonso: .243/.333/.493, 131 OPS+, 22% K

Shockingly similar, right? Alonso did hit 25 more homers – though he lags Walker in doubles/triples – so while he has a slight edge with the bat, it’s actually not been a large one.

But that’s just at the plate, and there’s more to baseball than hitting. Walker is the three-time defending Gold Glove winner at first base in the NL; he’s the best-fielding first baseman in the entire history of Statcast infield metrics (+57 Outs Above Average), dating back to 2016. It’s been consistent, too; aside from a 2021 cut short by an oblique injury, Walker’s OAA has been +15 (2019), +13 (2022), +12 (2013), and +13 (2024).

"He's a phenomenal player," Arizona GM Mike Hazen said recently. "He's the best defensive first baseman in baseball, and he's a self-made player in a lot of ways.”

Meanwhile, Alonso has been competent defensively at times – he was rated solidly enough in 2021 – but 2024 was a low point, and his career -24 OAA places him in the bottom-six of that since-2016 1B list.

Because of that huge difference in defense, and the similar offense, if you were to look at the first base Wins Above Replacement leaders over the last three seasons, you'll see that Walker is a top-five name at the position – above stars like Vladimir Guerrero Jr., and, yes, Alonso.

First base WAR leaders, 2022-24

• 18.7 Freddie Freeman
• 12.2 Matt Olson
• 11.4 Bryce Harper
• 11.3 Paul Goldschmidt
• 10.8 Walker ←
• 10.8 Yandy Diaz
• 10.1 Guerrero, Jr.
• 8.7 Alonso

So: Case closed. Walker’s a top-five first baseman -- only 10 hitters at any position have more homers than he does over the last three seasons -- and should be valued as such. Right? Not … exactly.

First of all, that list is what has happened, not what will happen, even if the past obviously informs the future to some extent. Going forward, you’d obviously pick Vlad Jr. over Walker, given the eight-year gap in their ages and Guerrero’s incredible 2024 year at the plate. But you’d also easily pick Walker over, say, Goldschmidt, given that Walker is three-and-a-half-years younger and Goldschmidt is clearly on the decline.

If Walker and Alonso were the same age, this might be an easy choice. But Walker, 34 in March, is more than three-and-a-half-years older than Alonso, who turns 30 on Dec. 7.

That they’re reaching free agency at the same time is in part because Walker kept getting stuck behind bigger-name, bigger-contract first basemen, dating back to when he was a fourth-round pick of the Orioles in 2012. That organization soon extended Chris Davis, traded for Mark Trumbo and developed Trey Mancini just as Walker was reaching the Majors, leaving little space. In the span of five weeks in early 2017, he was passed around on waivers between the Braves (who had Freeman), Reds (Joey Votto), and eventually the D-backs, who still had Goldschmidt for the next two seasons.

That meant that Walker spent nearly all of his age-26 and 27 seasons in Triple-A Reno, where he hit 50 homers before Goldschmidt was traded to the Cardinals following 2018. Entering 2019, at 28 years old, he had all of 99 career plate appearances. He now rates fourth on Arizona’s all-time home run list, with a special talent for mashing Clayton Kershaw.

It doesn’t change the age gap; it just helps explain why it’s there.

Which leads us to the ultimate question: It’s not that Walker is a better option over the five-, six-, or seven-year term that Alonso is likely seeking, because he’s not. There’s little doubt that you’d prefer Alonso from, say, 2027-30. It’s more like “which would you rather have over the next one, two, or three years – and then, after Walker is likely no longer a starter – would you rather have Alonso or the freedom to look elsewhere?”

So: Over the next three years, then? Walker’s age 34-36 seasons against Alonso’s 30-32 seasons, with the cost being “you don’t get Alonso’s seasons after that,” which some teams may not prefer anyway.

The first way to answer that is to see if there’s any visible signs of decline in Walker’s bat, and the answer seems to be: No, not yet. Walker’s hard-hit rate and barrel rate were each in the 85th-to-90th percentile – similar to or better than Alonso’s in each case – and while we have just one season of bat speed, his was in the 89th percentile. A bat speed comparison between him and Alonso shows a near perfect match.

While obviously age remains undefeated in the long run, if there’s a worry here, it’s with the recent memory of the three-year deal José Abreu signed with Houston that ended with him struggling so badly that he was released in Year 2. That, though, was a little different, as Abreu was already 36 at the time (after excellent years at 34 and 35) and there were already warning signs with velocity – signs that aren’t there for Walker.

The calculus might be, for many teams, that simply signing a deal unlikely to be more than three years (four at the absolute most) in Walker’s case is what they prefer out of a free agent first baseman. Looking back through history, there have been 22 contracts or extensions given to first basemen of at least $40 million total, which both Walker and Alonso ought to clear easily.

Five of those were for $200 million plus – a range neither player is going to reach – and while those all worked out great for the players, it’s safe to say that the teams that extended Davis (Orioles) and Miguel Cabrera (Tigers) or signed Albert Pujols (Angels) or Prince Fielder (Rangers) would have been a lot happier had they not finalized those deals. (Joey Votto’s 10-year-deal with the Reds is the outlier here.)

While signing big-money deals with slugging first baseman was in style 10 or 15 years ago, it’s telling how much has changed since Fielder, Ryan Howard and Pujols were getting theirs. Since 2016, only seven contracts of five-plus years for first basemen have been signed. For three of them (Davis, Cabrera and Eric Hosmer), the signing team was only too happy for the deal to end.

Two worked out well, thanks to Goldschmidt’s deal with St. Louis and Brandon Belt’s extension with San Francisco (though at $72 million, far less than Alonso is seeking). Two more (Freeman and Olson) are in-progress and off to good starts. All four of those success stories came via players who were more than just sluggers, as Freeman, Olson and Goldschmidt have all been Gold Glovers, while the sometimes-divisive Belt offered excellent plate discipline (and signed headed into his age-28 season, anyway).

If you were to look at the 2025 Steamer projections, you would see that Walker and Alonso are projected to be, once again, about identical as hitters, and obviously Walker carries the defensive edge. Time will change that at some point, but it doesn’t seem likely to be in 2025 – or possibly 2026, either. The new ZiPS projections have Walker as a league-average bat over the next three years, cumulatively.

It means that if you look at the teams in the bottom two-thirds of FanGraphs’s first base projections, it opens some doors. Only a few might be willing to go to the level Alonso is likely seeking, but if the price of entry is more like three years for Walker, that might increase the interest of some offense-needy teams like the Pirates, Nationals or Tigers. It also might make him more of a fit for win-now teams like the Astros or Yankees, or allow for a return to the D-backs, too.

Walker, obviously, doesn't have the name value or the raw power or the relative youth that Alonso does, and he'll get a smaller contract commensurate to all that. But he's also the type of player who may age just a little better, and may have more suitors due to that and the lesser commitment. When a 34-year-old first baseman gets a lot of interest this winter, don't be all that surprised.