Why Gomber Has Been So Good

Before the season started I had Austin Gomber pegged as a vital part of the Cardinals’ pitching staff. With the new three batter minimum rule set for the 2020 season, I envisioned the Cardinals would be forced to scale back usage of their specialists (like Tyler Webb) and expand the role of a lefty who could also be used against right-handers when the situation demanded it.

The offseason will allow for a deeper examination of the impact of the rule change, but it doesn’t feel like it effected player usage to a significant extent. The compressed schedule and season-long pitching crisis rarely left the Cardinals the luxury of choosing which relievers they used. The overall construction of the bullpen also factored in. Injuries and COVID forced the club to make judicious use of their starter-type relievers (Gomber, Gant, Reyes, Cabrera, Helsley, for example) in every conceivable role and often for extending outings.

So, I was right! Gomber has played a vital role in the staff. He has been as important as any other arm to the pitching staff’s success.

I was also wrong. The rule change had nothing to do with Gomber’s expanded role. The young lefty earned every inning he received by exceptional performance alone.

After missing most of the ’19 season with bicep and shoulder fatigue, Gomber re-entered the Memphis rotation in time for 8 starts and 45 innings. He managed a 2.98 era and a 4.00 FIP, with a K/9 of 10.32 and a 3.18 BB/9. The PCL was an offensive paradise last season. That sub-3 ERA is an amazing number and the 4.00 FIP is darn good as well. He allowed less than 1 HR/9.

All winter long Mozeliak kept reminding fans about Gomber, giving him equal attention with more interesting arms like Alex Reyes. Those mentions continued throughout Spring Training and Summer Camp. When games started and pitchers went down with injury, there was serious discussion about Gomber finding his way into the rotation.

It was not to be. Because of contract tracing protocols, Gomber found himself on the COVID-IL, with Ponce and Oviedo taking a starting role that surely would have been his.

For most of the season Gomber has instead filled the “pull-in-case-of-emergency” role that the club so desperately needed. Gomber has started three games. He’s pitched more than an inning 10 times in his thirteen appearances. He has even finished two games. He has seen actin in every inning - from the first through the ninth. Only Alex Reyes can come close to matching Gomber’s ridiculously diverse usage.

I shudder to think where the Cardinals would be without Gomber (and Reyes). In 25 innings, Gomber has a 1.80 era and a 3.46 FIP. His K rate is just under 9 and he’s allowing just .36 HR/9.

What has made him so good? There are four points I want to highlight:

1) A Fastball That Plays Up By Moving Down

Gomber’s statcast profile isn’t all that eye-popping. He has the look of a pitcher who hasn’t earned the exceptional ERA he sports. His xERA and xwOBA are both middle-of-the pack. His 4-seam fastball spin rate (just over 2000 rpm) and velocity (92.4 mph) are at or below average. Somehow, though, he has been able to limit hard contact and barreled balls.

His best pitch is his fastball and its value is deceptively high. Fangraphs gives Gomber’s 4-seam fastball a +6.0 value on the season. Pitch Info has it at +7.2. That’s a +2.48 weighted value per 100 pitches, good for 13^th in the league among pitchers with 20 or more innings.

How can a pitch with average or below velocity and spin rate be so effective? It’s all about the direction of the movement.

Gombers’ 4-seam fastball gains an extra inch of downward vertical movement over average – 13.4 inches of vertical drop overall. That has resulted in a 49.2% groundball rate and a 1.45 GB/FB ratio.

This downward movement and the ground balls it induces play into the Cardinals overall roster construction strategy. The club plays exceptional infield defense – especially when Edman is on the field – and Busch stadium is death to fly balls.

Gomber’s 4.5% HR/FB rate is silly low.

Still, it’s easy to see why Gomber’s ERA is outperforming his FIP and why his expected stats – xwOBA and xERA – point toward regression. While Gomber’s ground ball rates might hold up over more innings, that HR rate likely won’t.

2) A Complementary Curveball

Gomber has a four-pitch repertoire: fastball (54%), curveball (25%), slider (16%), and change (5%). This is a slight change over 2018 when Gomber’s slider was used almost interchangeably with his curve.

Is the increase in curveballs a good thing? Yes and no. By value, Gomber’s curve is his worst pitch at -1.1. That’s a significant regression over 2018, when the pitch was slightly above average. So, no, throwing more curves hasn’t been good from a value perspective. However, it is the right plan. Scouts have targeted Gomber’s curve as his best pitch since he entered pro ball and there are underlying indications that it is better than its weighted value suggests.

This will sound familiar: Gomber’s curve has a low spin rate and relatively weak horizontal movement. However, it has significant downward break – over 60 inches of total downward movement. Batters have hit the pitch harder than his fastball – .421 vs. .180 slug% – but the movement profile of the pitch, coupled with the fastball, contributes to Gomber’s high ground ball rate and low HR rates.

Expected stats support the Cardinals’ calling for more curves. His expected BA, Slug and wOBA are all lower than actual. This is an above-average pitch for Gomber that is likely suffering from some small sample size variance.

3) Slider with Exceptional Horizontal Movement

The increase in curveballs have come at the expense of Gomber’s developing slider. If Gomber just threw fastball/curve, both with downward movement, he would likely experience a significant drop in K’s. That’s how a groundball pitcher gets into trouble.

The slider helps temper that, even though he’s only throwing it 16% of the time. Gomber’s slider is generating a 35.1% whiff rate. It has exceptional horizontal movement – +2.5 inches compared to average – and Gomber locates it in the zone.

Gomber does not use his slider to get outs. It has the lowest put-away % of his four pitches. However, with hitters looking down/away (righties) or down/in (lefties), the slider up and in the zone is generating vital strikes when he needs them and allowing him to avoid throwing his FB/C combo near the center of the zone to often.

4) Command, Control, and BB rates

That brings me to command, control, and walk rates. Gomber’s walk percentage – 4.68 BB/9 – has not been good. I would ignore that. Gomber routinely had BB rates in the 2’s and 3’s while in the minors. In the minors, Gomber was probably able to get away with pitching in the zone. With only mediocre velocity, Gomber simply can’t throw pitches past major league hitters. Gomber has to live on the edges of the zone with his FB/CB combo:

This is why I like to separate between command and control. By my definitions, control is the ability to the pitches for strikes in the zone. Command is the ability to throw pitches where you want to throw them, even if that is out of the zone. Command is what really matters.

The heat map above demonstrates Gomber’s quality command of his FB/CB combo, despite his higher than desired BB rates. His FB and CB live on the bottom left side of the zone. Playing that close to the edges, Gomber has exchanged a higher-than-his-talent walk rate for the ability to remove the threat of home runs and hard-hit balls.

It’s a good exchange, even if it’s more extreme than it should be going forward. The small sample size of this season has a lot to do with this.

You can see Gomber’s ability to locate pitches outside of the center of the zone to generate enough K’s escape damage here:

What to Expect from Gomber in 2021

Gomber has made a strong case to be in the starting rotation next season. With uncertainty surrounding inuries to Dakota Hudson and Miles Mikolas, and Adam Wainwright’s pending free agency, there is likely to be some space for in the rotation. Is there enough to guarantee a spot to Gomber? Can he beat out Kim, Reyes, or Oviedo? Those will be great questions to address this offseason. If it works out for Gomber, expect a few more HR’s allowed but fewer walks and an end result that’s much closer to his current 3.46 FIP than his current 1.80 ERA. That’s still a solid starter at worst. I would like to see him have a shot at the rotation.

If it doesn’t happen, it’s no great loss. That will mean the Cardinals have 5 starters better than Gomber and that would be great news! Gomber could then return to the vital “pull-in-case-of-emergency” role where he has now proven he can thrive.