Will John Gant's Excellent ERA Adventure Turn Into a Bogus Journey?

John Gant’s 0.83 ERA is excellent. And that excellence has benefited the St. Louis Cardinals this young season. But Gant’s excellent ERA does not mean that the righty has pitched excellently.

Let’s look at the stats at Fangraphs through April 15, 2019, to see just how well Gant has pitched to date in order to get an idea of what we should expect moving forward.

Gant’s ERA is excellent, but misleading.

First, let’s remind ourselves of ERA’s flaws when it comes to measuring individual pitcher performance. Sure, it gives us an idea of how well a pitcher has suppressed run-scoring by the opposition. But the “earned” part means that the stat also has baked into it his team’s fielding and the official scorekeeper’s decision-making.

What’s more, a pitcher’s past ERA is not that predictive of the pitcher’s future ERA. This is particularly true for ERA over a small number of innings like Gant’s 11 2/3 through play on April 15, 2019. This is especially true for relievers. A reliever’s whole season is essentially a sample size of performance too small to allow for any meaningful projection moving forward.

All of this is to say that Gant’s ERA over about a dozen innings in early 2019 — in and of itself — doesn’t give one much reason to think that he will continue to have an excellent ERA throughout the season.

Gant issues too many walks.

Walks will kill you. There’s a reason that this has been common baseball knowledge going back generations.

On a micro level, walks are inherently bad. It’s easier to score a run from first base than from the batter’s box, so giving the other team a free pass puts them in a position where they are more likely to score a run. A pitcher who consistently makes it easier for the other team to score by walking batters is a pitcher who will have a harder time preventing the other team from scoring over the long haul.

Thinking more broadly, batting is an endeavor defined by failure. Even the greatest hitters of all time have made outs the majority of the time they have dug into the batter’s box. Consider Barry Bonds, who reached base safely the majority of the time in an astonishing four consecutive seasons. Even Bonds, who achieved such an astounding feat, made an out in 65.6% of his career plate appearances. As a general rule, the pitcher is more likely to succeed in a given faceoff than the batter.

What does this have to do with Gant? He issues too many free passes. Gant has walked too many batters as a reliever. The following table compares Gant’s 2019 BB% to that of all MLB relievers.

2019 BB%:  Gant vs. MLB Relievers

Gant	MLB RP	Gant +\- MLB RP
17.1	10.4	+6.7

That is way too many walks for almost any pitcher, let alone a righty like Gant who doesn’t notch many Ks.

Gant does not get enough strikeouts.

Gant has been decent at striking out opposing batters. His K rate has been a hair below the MLB reliever average for the young season. That’s not particularly good or very bad. It’s fine.

2019 K%:  Gant vs. MLB Relievers

Gant	MLB RP	Gant +\- MLB RP
22.0	23.8	-1.3

The problem such that one exists is not with Gant’s K rate standing alone. The problem comes when you pair it with his high walk rate. Relievers like Gant with walk rates well above average have trouble preventing the other team from scoring at a good rate (let alone an excellent one reflected by a sub-1.00 ERA). This is especially true if they don’t pair the high BB rate with a high K rate.

What’s more, Gant’s swinging-strike rate (SwStr%) does not lead us to believe that more strikeouts are coming. Gant induces a swinging strike 9.5% of the time, which is less than MLB relievers as a group, which do so 11.7% of the time. If anything, Gant’s SwStr% suggests that his K rate may be a little bit high right now.

Gant’s 100% left-on-base rate (LOB%) will drop.

To date, Gant has a 100 LOB%. This has been a great thing for the Cardinals! No batter Gant has walked has scored! How awesome!

It’s also completely unsustainable over the long haul.

On average, pitchers tend to strand a little less than three-quarters of the baserunners they allow to reach. So I tend to use the 75% mark as an indicator of sustainably in pitcher performance. Obviously, Gant’s ERA is reflective in no small part of his 100 LOB%. Given his average-ish rates of induces swinging strikes and Ks, there is not much reason to believe that his pitching will allow him to continue to post such a high LOB%.

Here’s how Gant’s LOB% compares to MLB relievers as a group.

LOB%:  Gant vs. MLB Relievers

Gant	MLB RP	Gant +\- MLB RP
100	72.9	+27.1

Lest you think that Gant has a skill for wriggling out of the jams that his penchant for walking batters creates, you should know that he posted a 69.9 LOB% in 2018, which was below the MLB rate for all pitchers of 72.8%. If Gant possesses such a skill, why didn’t he use it last year while starting? The answer, of course, is that Gant does not have such a skill.

For the rest of the season, it’s likely that Gant’s LOB% will be around 73% and his ERA will reflect it.

Gant will not continue to be effective against lefthanded batters.

Gant has a changeup. It’s a decent pitch. But the changeup does not make him a bona fide out-getter against opposing lefty hitters.

As a starter in 2018, the following table shows how lefthanded hitters performed against Gant as compared to righties overall.

Gant 2018

	TBF	K%	BB%	BA	OBP	SLG	wOBA	BABIP
vs. RHB	238	20.2	9.7	.224	.305	.324	.278	.272
vs. LHB	249	18.9	13.7	.208	.313	.349	.293	.235

Manager Mike Shildt has seen fit to deploy Gant for appearances against lefties and righties alike, presumably because of his history as a starter and changeup. To date this year, opposing lefty batters have done well against Gant even if their BA is low. Gant has issued seven walks to LHBs and allowed a homer.

Gant 2019

	TBF	K%	BB%	BA	OBP	SLG	wOBA	BABIP
vs. RHB	24	20.8	8.3	.091	.167	.091	.131	.118
vs. LHB	17	23.3	29.4	.083	.353	.333	.321	.000

There is little reason to believe that Gant will continue to hold down left batters the way he has so far. In fact, Gant’s tendency to walk lefties is the primary driver behind his poor pitching line to date. This echoes his 2018 performance as a starter. Gant’s topline success against lefthanded batsmen is based on the following formula:  High BB% + Low K% + Low BABIP. This is not a recipe for success moving forward.

Gant is not maximizing his potential.

I subscribe to The Athletic and you should too. One of the reasons is Joe Schwarz, with whom I used to write at Viva El Birdos. Joe wrote a fascinating post on Gant’s repertoire for The Athletic that you should read. To summarize in a way that doesn’t do his post justice, Gant’s slider has a dynamic profile that leads one to believe it could be a daunting weapon for the righty.

The problem is that Gant didn’t use his slider much in 2018, throwing it about 5% of the time according to the indispensable Brooks Baseball. While Gant is throwing his slider more often in 2019 at 9.59%, he is still not using it too terribly much. The near doubling of his slider usage is a positive development. But given the potential that Statcast data suggests the pitch has as detailed by Joe, Gant needs to be using it more often.

From now on, Gant will probably be just okay.

The point of this post is not to say that Gant has been bad. He has not been bad. This post is to show why Gant has not been excellent or even good.

In between good and bad is, like, just okay, man. And that seems fair as an expectation for the righty moving forward.

Fielding Independent Pitching (FIP) tries to isolate a pitcher’s individual performance from his teammates’ fielding and the scorekeeping by considering only Ks, BBs, homers, and innings pitched. Gant’s FIP sits at 4.52 entering play on April 16 vs. Milwaukee, which works out to a slightly worse than average 103 FIP- after adjusting for park effects.

Gant’s performance to date gives us reason to expect him to continue to pitch in a way that is not all that good or bad, just as meh as he has for the last couple of years. It would be unfair to expect a sub-1.00 or even sub 3.00 ERA from the righty reliever over the remainder of the year. Heck, we should be tickled pink with a sub-4.00 ERA from Gant this year unless something changes in his performance or usage.

Gant’s caliber of pitching to date makes him a useful arm for Shildt to use to sop up innings, but a scary one in high-leverage bullpen firefighting. It will be interesting to see how Shild deploys the righty moving forward. Will the new manager buy into the shiny ERA in a fit of Mathenaging or rely on Gant’s just-okay peripherals when choosing how to deploy the righty?