Pitching has been a thorn in the Los Angeles Angels’ side for years. The team’s lack of pitching is a major reason why the team has only been to the playoffs once in the Mike Trout era.

With Shohei Ohtani coming off an unprecedented MVP season and the addition of Noah Syndergaard, 2022 might be the turning point for the Angels. And the greatest key to their rotation might actually be the 23-year-old southpaw, José Suarez.

Proclaiming him as the potential key is surprising at first. He was fine in 2021, but he was far from outstanding. In 23 games (14 starts), Suarez accumulated 1.3 fWAR in 98.1 innings.

Here’s his line for the 2021 season, compared to MLB average:

Averageness is great for a back-end type, but it certainly doesn’t make him a key factor. At least not yet.

Once you begin to break down his pitch repertoire, however, Suarez potential is much more clear.

Despite using it over 40% of the time, Suarez’s 4-seamer was by far his worst pitch. Hitters essentially turned into Silver Slugger Austin Riley when they faced Suarez’s fastball. (The Braves 3rd baseman hit .302 and slugged .531 this year).

Of the 10 homers he allowed this year, 8 of them came on his fastball. Here’s one of them to Matt Olson:

If Suarez only threw his fastball, he’s not an average pitcher: he’s a pitcher you shouldn’t keep on the 26-man roster.

However, Suarez has a secret weapon. It’s one of the best pitches in all of baseball, and it makes his overreliance on his fast especially confusing.

His changeup, according to Baseball Savant, was worth -14 runs (where fewer runs are better). The 39th best rated pitch in MLB last season, batters hit just .145 and slugged .206 against the pitch. When hitters faced his changeup, they were hardly better than a pitcher at the plate (who hit .108 and slugged .137 this year).

It’s not pure stuff that makes his changeup so dominant. While it doesn’t impress with vertical drop our spin rate, Suarez locates this pitch with precision, unlike his fastball.

Compare his fastball location:

With his changeup location:

Suarez stays away from the upper half of the zone with his changeup. The upper half of the

zone, especially the corners is where Suarez got hammered this year.

Here’s Suarez staying down with his changeup:

This is a chart of batters wOBA against Suarez by location:

And here’s the location of his fastball on the Olson homer:

Half of the homers he gave up on his fastball were in zones 1, 2, or 3 this year. By staying away from these hot zones, Suarez was able to make his changeup a top-40 pitch in all of baseball.

But it wasn’t just his changeup that was successful this year. While his usage was light, his sinker was also similarly successful. While ineffective as a putout pitch (he did not record a single strikeout with the slowball), it still generated -3 runs. In 123 pitches, batters managed a .194 BA and .226 SLG. Suarez only allowed five hits the entire season (one double and zero homers) on the pitch.

His curveball, the worst of his secondaries, was still worth 0 runs and was used in 24% of his strikeouts.

An easy fix for Suarez is to change his usage rate for each pitch. Currently, his fastball, the worst of his four pitches, is thrown 40.1% of the time. He throws his changeup and curve 28.5% and 23.9% of the time, respectively. His sinker, while generating mostly positive results, is only thrown 7.5% of the time.

Going forward, Suarez should decrease his reliance on his 4-seamer. One solution is completely swapping the usage of his 4-seamer and sinker, while leaving the usage of his other two pitches the same. Instead of throwing his sinker 7.5% of the time, he could throw it around 30%-40% of his time, while only using his 4-seamer 5%-10%.

This can’t be the only adjustment Suarez makes, however. To explain this, we need to look at his performance as a starter versus his time as a reliever.

As a reliever, Suarez was quite good. He had a 1.98 ERA in 27.1 innings, though he did outperform his FIP and xFIP by a good bit.

As a starter his ERA ballooned to 4.44. His K% dropped 4% while his BB% rose .6%. While he had been very successful at leaving runners on as a reliever, he was worse than league average as a starter.

Suarez moved from the bullpen to the rotation at the beginning of July. All his relief appearances came in May and June.

This means that his monthly pitch usage nicely correlates to the time he spent in the bullpen (May and June) and the time he spent in the rotation (after July).

What’s interesting about his transition from starter to reliever is that he decreased his usage of his fastball.

As a reliever, Suarez threw his fastball 43.7% of the time in May and 47% of the time in June. While his fastball got hit hard in May, he held hitters to a .194 AVG in June (although hitters still slugged .452).

Once he joined the rotation, he decreased his reliance on his fastball and upped his usage of his curveball, from as low as 14.6% in May to as high as 26.2% in July.

He also began to use his sinker much more. He only threw it once in May and four times in June. In August, he threw it 14.2% of the time. Despite having incredible results, holding hitters to a .077 AVG and SLG, he reduced his usage to 9.8% in September.

Because of his declining fastball usage as a starter, his struggles can’t be solely attributed to his worst pitch.

It can, however, be explained by Suarez not trusting his best pitch as much.

As a reliever, Suarez used his changeup 41.1% of the time in May and 27.5% in June. While he upped his usage back slightly in July (30.2%), he relied on it less as the season went on.

To be successful, Suarez also needs to increase his changeup usage again.

He doesn’t need to use it as often as Milwaukee reliever, Devin Williams (who uses it 63.8% of the time), but it’s important to note that Suarez’s changeup actually has a better run value per 100 pitches (-2.9 compared to Williams’ -2.3).

If Suarez wanted to be bold, he could up his changeup to Williams’ rate. However, even a moderate increase of roughly 10% could significantly improve Suarez’s results as a starter.

By increasing his sinker usage by 10%, decreasing his 4-seam usage by 25%, and increasing his changeup by 10%, Suarez could be the key the Angels need to get to the postseason for the first time since 2014.

Of course, the Angels are certainly aware of this. In his final game, Suarez threw his changeup more than his fastball for the third time all year. He also upped his sinker usage to 15.3%. The result? Five innings of one run ball, allowing five baserunners against a Mariners team that was still in playoff contention.

The 45-second Skinny