Even with the loss of Shohei Ohtani to the National League and a pair of Hall of Fame candidates on the injured list, the American League West has a glut of pitching like no other.
Besides being home to the last two World Series winners and the last three AL champions, it’s the only division with a pair of three-time Cy Young Award winners. No other division had more 13-game winners in 2023. And now the highest paid reliever in baseball history calls the AL West home.
The top six pitchers on this list represent two teams, and the top four could be interchangeable depending on the evidence.
Without further ado, let’s examine the 10 best pitchers in the AL West.
10. LHP Reid Detmers, Los Angeles Angels
2023 Stats: 4-10, 148.2 IP, 4.48 ERA, 10.17 K/9, 2.5 fWAR
Had Cristian Javier of the Houston Astros not taken a step backwards last year, you might have seen him at No. 10 on this list. However, Detmers had the sixth-best fWAR of any pitcher in the division last season. (Sure, Javier started two of the last six no-hitters thrown over the past two seasons, but Detmers has actually completed the deed entirely on his own.)
Despite pitching just 15 games in the minor leagues, the 10th overall pick from the 2020 draft has been more than fine in his first few big league seasons.
The 24-year-old southpaw is the youngest pitcher represented on this list. There’s even a chance he could become the youngest Opening Day starter for the Halos since John Lackey in 2003, should new manager Ron Washington give him the honors.
Youth aside, Detmers struck out eight or more and allowed one or fewer runs in four consecutive starts in 2023. In the process, he joined an elite class of Angels starters: Nolan Ryan and Shohei Ohtani.
ZiPS and Steamer project Detmers for similar results in 2024 as he had the year before. If he pitches anything like he did in his final five starts — posting a 2.20 ERA and 29 K in 28.2 IP — he will continue to make further strides.
9. LHP Patrick Sandoval, Los Angeles Angels
2023 Stats: 7-13, 144.2 IP, 4.11 ERA, 7.96 K/9, 2.3 fWAR
Depending on which version of WAR you use, Sandoval was either slightly better than league average or the eighth-best pitcher in the AL West last season.
His year began with Team Mexico. He helped them upset Team USA in their opener and then twirled four scoreless frames in a loss to the eventual champions of the World Baseball Classic, Team Japan.
With the Angels, Sandoval was unable to recapture his performance from his breakout 2022 campaign. Strikeouts and ground balls were down, while walks and home runs were up. Still, he only surrendered 12 long balls, and his 0.61 HR/9 is the second-best in the majors since the start of 2022.
Sandoval was much better in the second half and managed to allow two runs or fewer in 10 of his final 13 starts. Hoping to rebound and lead a staff that will sorely miss Ohtani, the 27-year-old should keep pace with the back half of this group.
8. RHP Nathan Eovaldi, Texas Rangers
2023 Stats: 12-5, 144.0 IP, 3.63 ERA, 8.25 K/9, 2.5 fWAR
Few pitchers in the game today have two World Series rings like Eovaldi. Even fewer have a postseason resume like his.
Though he debuted back in 2011 at 21 years old, the 34-year-old has only gotten better with age. He’s one of only three starters in the division to be selected to the All-Star Game twice since 2021, an honor he first received at the age of 31.
The 2023 season was a tale of three stories for Eovaldi. Before a right forearm strain that cost him six weeks on the IL, Eovaldi was 11-3 with 2.69 ERA (37 ER/123.2 IP) in 19 starts. Afterwards, he went 1-2 with a 9.30 ERA (21 ER/20.1 IP) in 6 starts to end the regular season. In the postseason, he was the backbone of the rotation with a 2.94 ERA, helping to bring home the first Commissioner’s Trophy the franchise has seen in 61 seasons of play.
With so many of his rotation mates on the Rangers set to begin 2024 on the 60-day IL, Eovaldi has become the team’s ace out of necessity. If he can stay away from the trainer’s room and repeat his numbers from the first half of 2023, he can earn a player option worth $20 million for the 2025 season and set himself up nicely for another significant payday.
7. RHP Max Scherzer, Texas Rangers
2023 Stats: 13-6, 152.2 IP, 3.77 ERA, 10.26 K/9, 2.2 fWAR
Are Max Scherzer’s best days behind him? Almost certainly. Will he fight Father Time to make one more push at a Cy Young Award? Also yes.
Scherzer will miss the first half of the year following surgery to his lower back in December. (Similarly, teammate Jacob deGrom had elbow surgery last June, but while Texas expects him to return in August, there’s no certainty he’ll be the deGrominator of old right away.)
Considering Scherzer’s former teammate and regular rival Justin Verlander is a year-and-a-half older and was able to win a Cy Young Award at age 39, Mad Max will do everything in his power to do the same in the battle to be considered the greatest pitcher of his generation.
The 2023 campaign saw the righty post his lowest K/9 (10.26) since 2013 (10.08), but that mark was still the seventh-highest ever by a pitcher in his age-38 or older season (min. 100 IP).
Considering Scherzer will be pitching for his next contract this coming season, it’s a safe bet that he will continue to be a force when he returns.
6. LHP Josh Hader, Houston Astros
2023 Stats: 2-3, 33 SV in 38 SVO, 56.1 IP, 1.28 ERA, 13.58 K/9, 1.7 fWAR
It’s hard for any relief pitcher to have the same value as a starting pitcher. To see Houston hand out $95 million to Hader is proof positive that the left-handed closer has such worth.
Whether he pitches the ninth to preserve an Astros’ victory or sets up for the talented Ryan Pressly (90 saves since 2021, fourth-most in MLB), Hader will shorten games for the club that once counted him among their prospects during their rebuild in the early 2010s.
Aside from a brief hiccup of a season in 2022, Hader has been dominant for years. He still has a streak of five consecutive All-Star Game selections. Backed by a 2.60 ERA, 163 ERA+ and 15.1 K/9 since becoming a closer full-time for the Milwaukee Brewers in 2019, his 153 saves are the most in baseball.
No reliever has more seasons of 1.9 bWAR than Hader’s five since Mariano Rivera retired in 2013.
5. RHP Logan Gilbert, Seattle Mariners
2023 Stats: 13-7, 190.2 IP, 3.73 ERA, 8.92 K/9, 3.2 fWAR
The AL West is so deep with top of the rotation starters that Gilbert could win the AL Cy Young Award from spot No. 5 on this list and it would not be a huge surprise. His second full season looked a lot like his first with 32 starts, 3-plus WAR and nearly a strikeout per inning. While his home run rate went up, so did his ground ball-to-fly ball ratio.
A Stetson University product (like Jacob deGrom), Gilbert has performed better away from Safeco Field during his three years as a big leaguer. Last season, he had a 3.40 ERA in 16 starts away from home, winning nine games in the process, tied for the most road wins in the Junior Circuit.
In a rotation with Kirby and Luis Castillo, not to mention a pair of emerging rookies in Bryce Miller and Bryan Woo, you can bet Gilbert will continue to benefit from the healthy competition.
4. RHP Justin Verlander, Houston Astros
2023 Stats: 13-8, 162.1 IP, 3.22 ERA, 7.98 K/9, 3.3 fWAR
Five appearances in the World Series. Fourth-oldest Cy Young Award winner ever. Three no-hitters. An MVP. A staggering (at least in this era) 257 wins. 3,342 strikeouts that tie him for 12th all-time. You wouldn’t be wrong to think this first-ballot Hall of Famer who won the 2022 AL Cy Young and followed it up with a 3.22 ERA should be No. 1 on this list.
Verlander didn’t begin the 2023 season until May because of a right teres major strain. When he found his rhythm, he went 4-1 with a 1.49 ERA over seven starts before being traded back to Houston.
The 41-year-old simply isn’t slowing down. His strikeouts took a noticeable dip last season and his earned run average may have benefited from some good fortune, but Verlander is far from done. He may be in the 54th percentile in terms of average fastball velocity now, but he just doesn’t need to overpower like he did during his days with the Detroit Tigers in order to be effective.
3. RHP George Kirby, Seattle Mariners
2023 Stats: 13-10, 190.2 IP, 3.35 ERA, 8.12 K/9, 4.4 fWAR
No pitcher has the control of George Kirby. None.
In only his second season as a big leaguer, Kirby walked 19 batters in 190.2 innings. That’s it. Coupled with his ability to miss bats, his 7.64 strikeout-to-walk ratio (275 K, 36 BB) was the highest in Major League Baseball history through a pitcher’s first 50 career starts. He’s also the youngest player with a 9-to-1 strikeout-to-walk ratio in a single season (min. 190 innings) since the start of the modern era in 1901.
Tied with Framber Valdez for most quality starts last season with 20, Kirby also had 12 QS without a walk, the most in baseball history for a pitcher age-25 or younger. He also went seven innings or more in 11 outings, third-most in the AL.
Bank on Kirby to continue to establish himself in 2024 and possibly elevate his profile to that of the best pitcher in the American League.
2. LHP Framber Valdez, Houston Astros
2023 Stats: 12-11, 198.0 IP, 3.45 ERA, 9.09 K/9, 4.3 fWAR
There’s one starting pitcher you should be talking about a lot more: Framber Valdez.
Just look at his no-hitter on Aug. 1 against the Cleveland Guardians last season. It required only 93 pitches, the third-fewest in a no-no since the advent of pitching tracking in 1988. Valdez surrendered only three fly balls and induced 12 ground outs to become the first lefty in ‘Stros history to toss a no-hitter.
Since ground ball rate became a recorded stat in 1987, his career ground ball percentage (63.4%) is the 5th highest ever posted by a starter.
No-hitter aside, Valdez is more consistent than dominant, with 46 quality starts since 2022, the most in Major League Baseball. Only seven pitchers who have made as many starts as Valdez since the beginning of 2020 have an ERA lower than his 3.19 mark. Four of those pitchers have a Cy Young Award for their work, and the other three have at least a third-place finish. Valdez, who received some MVP recognition in 2022 and CYA votes in three of the last four campaigns, has finished no higher than fifth.
Don’t be surprised if he wins the award in 2024. Remember where you heard it first.
1. RHP Luis Castillo, Seattle Mariners
2023 Stats: 14-9, 197.0 IP, 3.34 ERA, 10.01 K/9, 3.4 fWAR
The Seattle Mariners traded a bounty of top-flight prospects for Luis Castillo in 2022. They locked up the right-handed ace to a five-year, $108 million deal soon after. Then, he turned around and dominated for 7.1 innings on the road in the M’s first postseason game in 21 years.
His 2023 was more of the same, making an AL-leading 33 starts and striking out 217 en route to a fifth-place finish for the AL Cy Young Award. That performance was only the eighth of 200+ Ks in franchise history and the first since Félix Hernández in 2014.
Castillo had 511 swing-and-misses in total, the most in the AL, to go along with the third-lowest opponents’ batting average (.218) thanks to a fastball velocity (96.4 mph) higher than any starter in the division.
Projected to be the best starter in the division once again according to ZiPS, the 31-year-old from the Dominican Republic is the ace of the aces in the AL West.