What to expect from Mariners SP Luis Castillo in 2023

Since 2019, Luis Castillo has been one of the best pitchers in the league but has flown under the radar due to playing for the Cincinnati Reds, a team that has spent most of that time in the bottom of the NL Central.

He throws hard, gets batters to swing and miss with a nasty changeup and sinker combination, misses barrels and is generally all-around a dominant starter and is certainly ace of staff material.

For the Reds, over five and a half seasons, Castillo went 44-53 with a 3.62 ERA over 792.1 Innings of work. He had 860 strikeouts to 287 walks, 3.0 strikeouts per walk, and his ERA+ of 125 showed that he was as consistently good as they come.

His best season in terms of pure “stuff” was 2019, but his best statistical season was arguably in 2022.

Baseball Savant shows that in 2019, he was nearly all red circles. He was red in average exit velocity (83rd percentile), hard hit % (74th), xERA (84th), xBA (87th), xSLG (93rd), barrel % (84th), K% (81st), whiff % (94th) and chase rate (80th). He was also named to his first career All-Star game and was crucial for the Reds' success.

However, in 2022, he was an All-Star once again and split time between the Reds and Mariners. Over the entire year, he went 8-6 with a 2.99 ERA over 150.1 innings. He had 167 strikeouts to 45 walks and gave up 13 home runs. Despite overall production going down when moving to Seattle, he still improved his SO/W all the way up to 4.53.

Now, fully on the Seattle Mariners, fresh off their first postseason appearance since 2001, he comes into 2023 as a potential Cy Young Award candidate. So now let's look at some projections for how he will do in the upcoming season.

	IP	ERA	SO	Wins	WHIP	BB/9	HR
B-Ball Ref	154	3.51	161	8	1.227	3.1	15
Fangraphs	194	3.17	202	12	1.150	2.9	18
SoDo Mojo - Chris O'Day	192	2.51	252	16	1.045	2.1	17

But what do I think is going to happen? To determine that, I have set three seperate potential outcomes for Castillo. I put my best, median, and worst case scenario on what we can expect in 2023.

	IP	ERA	SO	Wins	WHIP	BB/9	HR
Best	202	2.24	252	16	1.002	2.5	16
Median	175	2.94	200	14	1.102	2.9	16
Worst	149	3.77	163	10	1.329	3.4	19

I expect that we will see a statline very similar to the median prediction in 2023, but my hope is that we see the best case and he is the 2023 AL Cy Young. If that is to happen, I do not think it is a stretch to say that the Mariners may be one of the best teams in the league next season.

Schedule