Why Spencer Horwitz may have been the best first base choice for the Pirates

The Pittsburgh Pirates' most significant offseason addition thus far has been Spencer Horwitz, acquired from the Toronto Blue Jays by way of the Cleveland Guardians. Horwitz could be the best first baseman the Pirates have had in decades, and while that isn't a very high bar to surpass, he could end up being one of the biggest improvements any team has made at first base across MLB this offseason.

Horwitz had an impressive rookie season. He hit .265/.357/.433 with a .344 wOBA, 125 OPS+, and 127 wRC+ through 381 plate appearances. He provides enough pop at first base to stick at the position, as he went yard a dozen times with an above-average .168 isolated slugging percentage. The league-average first baseman had a .164 ISO last year. Horwitz didn't sell out for power, though; instead, he kept his K% under control with just an 18.4% K%. He also drew walks at a healthy 11% rate. All told, he had a +1.9 fWAR (average of +3.0 fWAR/600 plate appearances).

It's not as if Horwitz greatly overperformed, either. He was in the 60th percentile or greater in xBA (.254), xSLG% (.419), and xwOBA (.334). His 8% barrel rate was about league average as well. Horwitz was also well above average in other batted-ball metrics like squared-up rate (27.3%, 72nd percentile) and launch angle sweet-spot rate (37.4%, 81st percentile). Horwitz displayed strong plate discipline. He only swung outside the zone 25.7% of the time, which placed him among the 69th percentile of batters. His swing-and-miss rate of 19.4% was in the 79th percentile. Just 67 of 282 batters had a sub-20% whiff percentage.

Horwitz was one of baseball's best rookies last season when he stepped into the batter's box. There were 31 rookies in 2024 with at least 300 plate appearances. Horwitz had the seventh-best OPS, fifth-best wOBA, third-best OPS+, and the fifth-best wRC+. He wasn't that far behind National League Rookie of the Year finalist Jackson Merrill, who had a .826 OPS, .352 wOBA, 127 OPS+, and 130 wRC+. He was also above fellow AL rookie standouts in each of those four stats, including Wyatt Langford, Wilyer Abreu, and Austin Wells.

He was even better than American League Rookie of the Year winner Colton Cowser on a rate basis. Cowser hit .242/.321/.447 with a .331 wOBA, 120 wRC+, and 123 OPS+ in 2024. He walked 9.3% of the time but struck out in 30.7% of his plate appearances. The only rate statistic where Cowser outdid Horwitz in was slugging percentage and isolated slugging percentage, but Horwitz drew walks, struck out (a lot) less, got more hits, and got on base more frequently than Cowser did.

Pirates' Spencer Horwitz outclassed many 2024 rookies, outranks recently traded top first basemen

Horwitz also stands out among other first basemen who were recently traded. Josh Naylor batted .243/.320/.456 with a .332 wOBA and 118 wRC+ in 2024. Naylor had a 9.2% walk rate and 16.9% K%. Sure, he hit for more power and struck out slightly less frequently than Horwitz, but Horwitz walked more frequently. Naylor had a near-identical .335 xwOBA and xBA (.257), albeit a better xSLG% (.443). Horwitz also didn't struggle after the All-Star break, whereas Naylor put up an unimpressive .717 OPS, .312 wOBA, and 105 wRC+ in the second half of the season. Naylor has also been attached to rumors surrounding potential weight issues, something Horwitz hasn't dealt with. Naylor will be an Arizona Diamondback for the 2025 season, then will hit free agency.

Lowe is coming off a season that is more comparable to Horwitz's campaign. He hit .265/.361/.401 with a .337 wOBA and 121 wRC+. Both Horwitz and Lowe had near-identical batting averages and on-base percentages. Lowe hit for less power, however, with 16 homers in 565 plate appearances and a .136 isolated slugging percentage. He had a slightly better walk rate than Horwitz at 12.6%, but a worse K% at 22.1%. Lowe had a worse xwOBA (.329), xBA (.252), and xSLG% (.380) than Horwitz as well.

Granted, Horwitz was only in his rookie season, didn't even reach 400 plate appearances, and doesn't have the track record that both Naylor and Lowe have. But how a player did in 2023 and especially 2022 should not have a significant impact on projecting how that player will do in 2025. Horwitz did not have an insignificant amount of plate appearances last season, either, and is younger than both Lowe and Naylor. 

Sure, Horwitz does possess a few red flags, and we won't be ignoring them here. He was very productive when facing right-handers, owning a .864 OPS, .373 wOBA, and 147 wRC+. He ranked in the top 25 in each of those three metrics among batters with at least 300 PAs against RHP. But when he had to face a lefty, Horwitz had a meager .522 OPS, .239 wOBA, and 53 wRC+. However, his playing time against LHP was limited, as he only had 81 plate appearances, and he still carried a solid 8.6% walk rate and 17.3% strikeout rate when facing a southpaw. If worst comes to worst, then the Pirates can find a short-side platoon bat to help shield Horwitz from lefties.

It's also easy to make the comparison to Naylor. When Naylor was first given regular playing time in 2022, he was just as helpless against lefty pitching as Horwitz was this year. Naylor had a .522 OPS, .241 wOBA, and 54 wRC+. Last year, he improved to a playable .715 OPS, .311 wOBA, and 104 wRC+. Naylor was only one year younger in 2022 than Horwitz was in 2024.

Fans may also argue that the Pirates overpaid for Horwitz, as they gave up Luis Ortiz, along with prospects Josh Hartle and Michael Kennedy. The Arizona Diamondbacks, meanwhile, gave up just one pitcher in Slade Cecconi in exchange for Naylor, while the Washington Nationals traded reliever Robert Garcia for Lowe. But as fellow staff writer Baron Dionis recently pointed out, the price for both Naylor and Lowe may not have been as cheap as it may seem. Garcia had some outstanding underlying numbers despite a poor ERA. Cecconi may not have induced good results, but has strong stuff that could be significantly improved upon by the right guidance. 

Sure, Ortiz also has good stuff that he could improve upon, but he also had some poor underlying numbers, including a SIERA, xERA, and xFIP over 4.00 while being below average in both exit velocity and barrel percentage. Hartle has just a single professional game under his belt. Kennedy pitched well in his first extended look in pro ball, but has yet to be fully tested. He only has 10.2 innings pitched above A-Ball. 

Horwitz is also a long-term investment, as he is controlled through 2029. Naylor only comes with control through 2025, and Lowe is a free agent after the 2026 season. There is no denying a short-term investment can be more productive than a long-term investment. But after what all three showed in 2024, Horwitz looks like he could be just as good as Naylor, and especially Lowe.

Horwitz will have plenty of time and chances to improve against lefties and prove to be a worthwhile investment. The Pirates brought in Horwitz's former hitting coach, both in the minor leagues and major leagues, in Matt Hague. Too many fans may be getting caught up in the fact Horwitz isn't a name-brand talent like Josh Naylor or Nathaniel Lowe, but he's coming off a strong rookie season, has plenty of time and room for improvement, and could be the first steady presence the Pirates have had at first base in quite some time.