Christian Walker Is Having a Righteous Walk Year

He may not be playing in Arlington tonight, but Christian Walker just wrapped up an All-Star level first half. The Diamondbacks first baseman came into the All-Star break ranked third in the National League with 22 home runs, fifth with 66 RBI, and among the top 15 qualified batters in wOBA (.357), xwOBA (.365), and wRC+ (131). His 10 OAA are third-most among NL fielders, while his 7 DRS, 4.1 UZR, and 8 FRV are all the top marks at his position. Thanks to his spectacular defensive performance, the two-time Gold Glove winner is the only qualified NL first baseman who has provided positive defensive value at first despite the hefty positional adjustment. On top of that, he has played in all 97 of Arizona’s games so far, putting him on pace for more than 700 plate appearances this season.

Add his offense, defense, and durability together and you get 2.9 WAR, which places Walker in the top 15 among NL position players and top 30 in the majors. Considering that 46 position players were invited to the Midsummer Classic this year, it’s hard to deny that Walker is having an All-Star worthy season. At the same time, it’s also hard to get too fired to up about his “snub.” Bryce Harper and Freddie Freeman have put up superior offensive numbers and WAR totals, rightfully earning the two guaranteed spots for first basemen on the NL roster. In addition, three NL players with more WAR and arguably even stronger All-Star cases than Walker were also left off the squad: Francisco Lindor, Brandon Nimmo, and Willy Adames. Finally, this isn’t even the most disappointing time Walker has missed out on a trip back to Globe Life Field within the past 10 months. Still, it’s a shame that Walker’s excellent first half will go unrewarded. At 33 years old, the late bloomer is putting together the best season of his career at the plate and in the field. Surely, that deserves to be celebrated.

At this point, Walker is used to being underestimated. He has been a regression candidate since the moment he first tasted big league success. Following his breakout rookie season in 2019 (111 wRC+, 3.0 WAR) ZiPS projected a step back in ’20; as Dan Szymborski put it, “The projections aren’t completely sold on Christian Walker, still seeing him as a league-average first baseman.”

It’s not difficult to understand why ZiPS was skeptical of Walker. At 29 years old, he had only one successful major league season under his belt, and no projection system could expect him to maintain his ridiculous defensive numbers at first base. ZiPS wasn’t wrong, either, as he took a significant step back in 2020 and an even bigger step back in ’21. Thus, the system was still skeptical of Walker after his second breakout season in 2022. Although Walker slugged 36 home runs, led first basemen with 14 OAA, and finished with 4.0 WAR, Dan included him on his list of ZiPS bust hitters entering 2023, describing him as “clearly not a star, just a good league-average first baseman coming off a peak year.” Yet, lo and behold, Walker almost perfectly replicated his 2022 season in ’23. He finished with a 120 wRC+ and 3.9 WAR, while deservedly winning his second Gold Glove in as many years. To be clear, I don’t bring this up to dunk on ZiPS, but rather to demonstrate how many times Walker has exceeded expectations in his unusual career.

Indeed, ZiPS underestimated Walker once again heading into 2024; he has already surpassed his preseason 2.7 WAR projection according to ZiPS Depth Charts. However, the fact that projection systems (and ZiPS is hardly the only one) keep selling Walker short is a feature, not a bug. A good projection system isn’t going to expect a career-best performance from a player as he enters his mid-30s. Projections systems are built on historical comps, and Walker has defied the typical progression of a major league career. In his age-33 season, he is on pace for career-highs in plate appearances, games played, home runs, RBI, runs scored, wOBA, xwOBA, wRC+, OAA, FRV, and WAR:

When Walker spoke to David Laurila ahead of the 2023 season, he explained how “data and hard numbers” have helped him trust his process during difficult stretches. Missing out on an All-Star nod amid what could be the best season of his career is surely disappointing, but as long as he focuses on the data and hard numbers, he should be nothing but pleased with his first-half performance.

Underlying Walker’s career-best 131 wRC+ is a career-best 103.4 EV50 (the average exit velocity of the hardest 50% of his batted balls) and a career-best 36.3% sweet-spot rate, resulting in a career-best 15.7% barrel rate. He has also increased his pull rate and lowered his opposite field rate on fly balls. In fact, nearly all of his extra-base hits have been pulled this year, which stands out compared to last year, when he sprayed the ball to all fields:

This could be a warning sign that Walker is selling out to pull more fastballs as he ages. However, I’m not seeing many other indications of age-related decline. His bat speed is elite (92nd percentile), and his whiff rate remains essentially unchanged from last season. Moreover, he has done more damage on curveballs (+4 run value, per Baseball Savant), changeups (+4), and sweepers (+4) than he has on all other pitches this season. That’s not what you’d expect from a hitter sitting fastball.

That said, Walker is striking out noticeably more often this season (25.2%) than he did in 2023 (19.2%), to the point that no qualified NL batter has seen a larger increase in strikeout rate. However, it’s hard to worry too much about this development after looking at Walker’s underlying plate discipline data. Both his whiff rate (misses as a percentage of swings) and his swinging-strike rate (swings and misses as a percentage of all pitches) are ever so slightly down from last season. So is his chase rate. What’s more, his first-pitch strike rate is down from 60.2% to 55.7%. Only three qualified NL batters have seen a lower rate of first-pitch strikes this season, and no NL batter has started more plate appearances ahead in the count. As you’d expect, Walker has done quite well for himself when he starts out 1-0, posting a 186 wRC+. Unfortunately, he has been worse than in past years when he gets into an 0-1 hole (75 wRC+). But that’s been happening less often, so the tradeoff certainly seems to be worth it.

All this is to say, I’m inclined to believe Walker’s rising strikeout rate is the result of conscious decision-making at the plate rather than an inability to keep up with opposing pitchers. Consider this: Walker has been far more likely to whiff with two strikes this season than he was in 2022 or ’23, yet his wOBA, xwOBA, and run value in two-strike counts are all higher this year than in any other full season. My apologies if you’re tired of reading about all the ways in which Walker is having a career-best season, but you’re going to have to take that up with the man himself.

As luck would have it, Walker is enjoying this excellent season with his first foray into free agency on the horizon. Thus, his name has come up in a bit of trade speculation; earlier this month, Jon Heyman called Walker the Astros’ “dream target” ahead of the deadline. It seems unlikely that the reigning NL champs would sell this summer, especially not now that they are back above .500 and just a game behind the Mets for the final wild card spot, but it’s worth mentioning that on July 1 general manager Mike Hazen would not commit to buying when asked about his deadline plans. Perhaps the fact that his team has gone 8-5 since his comments has changed his mind, but then again, a losing streak after the All-Star break could swing the pendulum back in the opposite direction. Even if the Diamondbacks don’t buy at the deadline, I’d expect them to stand pat. Their best bet could be to hope that Corbin Carroll turns his season around and veteran starters Jordan Montgomery, Eduardo Rodriguez, and Merrill Kelly return strong and healthy from the IL. However, if things go especially poorly in the 10 games between the All-Star break and the deadline, perhaps Hazen can be swayed by a strong enough offer for Walker. After all, Walker could be the best rental and one of the few impact bats available on a seller’s market.

Still, the more likely outcome is that Walker remains with the D-backs come July 31. In that case, the team will surely extend him a qualifying offer after the season, and he will almost surely decline, setting himself up to test free agency for the first time.

I find it more than a little frustrating that a player who made his MLB debut at 23 years old in 2014 will not become a free agent until the 2024-25 offseason, ahead of his age-34 campaign. Most players in a similar situation would have lost their peak earning years to the artificial constraints of the arbitration system. However, in Walker’s unusual case, he might just be reaching free agency at the perfect moment. During spring training, he told The Arizona Republic’s Nick Piecoro how proud he is to feel like he’ll have legitimate leverage to wield as a free agent: “It’s a sense of accomplishment… We have the ball in our court. It hasn’t always felt that way.” And that was before he put together the best first-half performance of his career.

Christian Walker might not be an All-Star, but he is playing the best baseball of his career, and he’s setting himself up nicely for free agency this winter.