by Matt Korte

Will the 2020 Reds have plate discipline?

No one stat can ever tell the full story of a player. There are countless different skills of ball players that can be quantified and qualified in just as many ways. That being said, I will focus on individual single stats for every Reds player in hopes to further understand the players holistically. This article will focus on O-Swing% and how the Reds compare to each other and to the rest of the majors.


O-Swing% (chase percentage) is a simple stat that requires little explanation. The number is the percentage of times a batter swings at a pitch that is outside of the strike zone. Despite the simplicity of the stat, it has some meaningful implications when it comes to batters getting on base. Common sense would tell you that the more often a batter swings at bad pitches (ones outside of the strike zone), the less likely he is to get on base. In this case, your common sense is right!

Looking at qualifying batters over the past three seasons, there seems to be a correlation between O-Swing% and xOBP. Batters who swing less at bad pitches have a higher expected on base percentage. So now let’s take a look at the Reds current roster and see how they have performed in terms of O-Swing% in 2019.

(Note: Shogo Akiyama is not included in this article as there is no record of O-Swing% in the NPB.)

Bad (0 – 10th Percentile of MLB)

Baseball Savant logged the “Punisher” as the worst returning offender of swinging at bad pitches for the Redlegs. I was curious to see if his now-infamous August/September splits played a big role in this, but they were surprisingly similar, with only a 0.2% increase between the two months. One thing that did change more drastically was pitchers realizing that they didn’t necessarily have to pitch within the zone to get Aquino out. Opposing pitchers went from putting an already low 41.0% of pitches in the zone in August to 38.5% in September when facing Aquino knowing that the rookie was susceptible to swing at those outside pitches.

Newcomer Nick Castellanos posted an all-time high in O-Swing% this past season, but it turns out the slugger’s outlook in this aspect may not be overly concerning. Not only was Castellanos frequently swinging at pitches outside of the zone, he was swinging at everything. In 2019 the outfielder formerly known as Nicholas swung at 54.7% of all pitches, which was 13th most in all of baseball. Nick was able to do this while maintaining a slightly below league average 21.5 K%, so his high volume of swings shouldn’t hold him back in 2020.

Not far behind Castellanos in Swing% is Freddy Galvis at 54.0%. As seen above, Galvis has regressed the past three years in both O-Swing% and xOBP. Each of the past three seasons his K% has increased which is concerning but comes with a tradeoff. 2019 was a career year for the shortstop in terms of power as he posted a career high in ISO at .178 which was largely in part to increasing his barrel usage to 5.5% and hard hit % to 36.1%. If the power stays, you can live with Galvis being swing happy.

Of note here is that Jose Iglesias swung at an astonishing 45.8% of pitches outside of the zone in the MLB last year, which was third worst out of 300+ qualifying batters. So, while Galvis may leave much to be desired, he still does stand as an upgrade over Iglesias especially if his power holds up.

Wrapping up this tier is Kyle Farmer, who had the fewest plate appearances of anyone on this list (198), so his 37.9 O-Swing% should be taken with a grain of salt. It is most likely premature to make a judgement on Farmer because of his small sample size, but should be something we keep an eye on moving forward.

Below Average (10-50th Percentile of MLB)

The knock on “Moose” when the Reds signed him to a four-year contract this winter was that he didn’t help the Reds in what they lacked most in 2019, on base percentage (OBP). Personally, I think that Moustakas is more than proficient in getting on base as he boasted a .329 OBP and .348 wOBA which are both well above not only Cincinnati’s average, but the league average as well. Sure, Moose could stand to improve his O-Swing%, but it seems to not hurt him with his K% five points below the MLB average.

Average (50-60th Percentile of MLB)

In the middle of the pack stands Tucker Barnhart who started off his career with a high chase rate, lowered it for a stretch of three years, and saw it creep back up again in 2019. The opposite occurred to most of his batting metrics as he had a career low xwOBA of .280, which was in the bottom 4% of the big leagues. Another career high in his 22.8 K% surely did not help his cause. The case has been made throughout the offseason that the Reds should improve behind the plate, but it seems like the Reds value what Barnhart brings defensively enough to outweigh his abysmal showing at the plate in 2019.

Nick Senzel has been the focus of many offseason conversations, whether it has been about his trade value or where he can fit into the lineup. As seen above, Senzel started off his rookie campaign with great plate discipline but saw a drastic change by midsummer. His September O-Swing% can be disregarded as it is a small sample size relative to the other months and provokes the question of why he changed his approach progressively through the season. It could be as simple as him taking a less conservative approach after getting more comfortable in the majors, or even that he was attempting to hit for more power as David Bell played him in the leadoff spot less often in July and August. Whatever it is, the hope for Senzel is that he can find his role within the club and produce. Plate discipline is a great place to start.

Above Average (60-80th Percentile of MLB)

For as much as Phillip Ervin absolutely rakes against lefties (164 wRC+) compared to righties (67 wRC+), his O-Swing% splits are surprisingly near identical. In 2019, Ervin only chased 26.8% of the time against RHPs and 26.3% of the time when facing LHPs. This seems to go against his slightly better K% and BB% when hitting left handers. The reason for this could be because Ervin is swinging and missing on pitches in the strike zone nearly twice as much against RHPs (22.5%) than against LHPs (13.1%). While his plate discipline remains constant facing either handed pitcher, it is his proclivity to swing and miss against righties that sank his K%, BB%, and overall batting success.

By all accounts Eugenio Suarez had an amazing 2019, with his career high Barrel % (14.0%) and launch angle (17.8) being large reasons for the boost in power. His ISO skyrocketed to .301, which was nearly 60 points above his previous best. One side effect of the increase in power was his plate discipline, with a career high in K% at 28.5% and a three-year high O-Swing% at 24.1%. In this case, there shouldn’t be too much cause for concern, as his BB% stayed above league average at 10.6% and his overall Swing % of 44.4% is near the bottom of qualified batters in the league.

Good (80-90th Percentile of MLB)

Now heading into the top 20% of the league, Josh VanMeter may come as a surprise to some. This isn’t due to small sample size either, as he had over 250 plate appearances in his rookie season. VanMeter measures up as a league average hitter in many metrics, but one area he shines through is his plate discipline. His 22.1 O-Swing% translated to a well above average 11.2 BB%, which we hope he can sustain going into 2020.

To the shock of no one, the man who had Joey Votto as his mentor excels in not chasing bad pitches. Winker saw his O-Swing% go up over the past two seasons, but still sits just outside of the top 10% of the league. That might speak more to how great his O-Swing% was last year (17.6%), than how it was higher in 2019. Regardless, 2019 was a down year for Winker at the plate with his career low BB%, increased K%, and extremely small launch angle of 7.4 degrees.

Elite (90-100th Percentile of MLB)

Last season, Curt Casali broke out as the better hitting option of the two Reds catchers. He has a career O-Swing% of 21.7%, so his 2019 number is not a fluke. But at the same time, O-Swing% is not all that you look for in a hitter. In fact, of the 30 batters with the lowest O-Swing% in 2019, Casali had the second lowest xOBP to Garrett Hampson with .319 and .283, respectively. A lot of this can be accounted to his high 25.0 K%, which certainly does not help xOBP. If Casali can rein in his K% to around the 20.5% he had in 2018, the Reds’ need for hitting from the catcher position could be resolved in house.

That leaves Joseph Daniel Votto. All things considered, Votto had an off year as far as O-Swing% is concerned. The MLB leader in plate discipline in 2015, 2017, and 2018 out of qualified batters, Votto suffered a down year in nearly all fronts last season. That being said, Votto is still firmly positioned as the MLB’s poster boy for plate discipline, and deservedly so.

In an off year, Votto still posted one of the lowest Swing% rates in the MLB (41.5%), but suffered in what has typically been his calling card, OBP. For the just the second time in the last ten years, Votto was not one of the top three OBP performers in the majors. Even more damning was the fact that his .357 OBP last season was the worst in his career, with only his first full year in the big leagues in the same ballpark. MLB has tracked O-Swing% for the past five seasons, and Votto had his second worst rate which undoubtedly helped lower his OBP. Whatever Votto did to change his approach last season clearly didn’t work. Let’s hope for the sake of the 2020 Reds (and the 2021-2024 Reds) that Votto is able to go back to his bread and butter: not swinging at bad pitches.

What to expect from the 2020 Reds

The 2019 Reds had an O-Swing% that was more than a full percentage point higher than the MLB average and, in no coincidence, had an OBP well below the league average as well. The goal of the offseason was to bolster the Reds’ on-base presence, but outside of Shogo Akiyama — who is still somewhat of an unknown — the Reds weren’t able to sign players who excel in that trade.

When looking at O-Swing%, the additions of Galvis (last season), Moustakas, and Castellanos might be improvements over who they are replacing, but relative to the rest of the league are not helpful in plate discipline. If Votto is able to return to his super elite form, the Reds will regain an on-base machine that will join a solid core of smart hitters in Casali, Winker, VanMeter, Suarez, Ervin, Senzel, and Barnhart. The goal is that the rest of the team can follow suit. Not chasing pitches leads to getting on base and getting on base leads to scoring runs. It’s truly as simple as that.

[Featured image:]

Note: Please welcome Matt Korte to Reds Content Plus. He’s one of our new writers.

Matt Korte is a lifelong Reds fan despite living most of his life in Michigan. The first five years of his life were spent in Cincinnati, but Matt became a lifetime fan when revisiting Cincinnati and watching Brandon Phillips hit a grand slam to defeat a Barry Bonds led Giants team in 2007 with his father. He hopes to one day see a Cincinnati sports team advance in the playoffs for the first time in his lifespan. A recent BS and MBA graduate, Matt currently works at Concordia University Ann Arbor as the Assistant Sports Information Director. When not working, you can find him consuming as much Reds, Bengals, fantasy sports, Star Wars, and Survivor content as possible. You can catch Matt on Twitter at @MKorte7815 where he can be found discussing all of the above.

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9 months ago

Lots of details and information – articulated quite well. Nice article Korte!

Jefferson Green
Jefferson Green
9 months ago

Thanks, Matt – welcome!
Question: do you know how O-Swing% trends late in careers (i.e. Votto, but other players, too)? As bat speed slows, it would hold that the hitter has to decide earlier whether a pitch is a strike, and these earlier decisions would lead to higher O-Swing% and a higher K%. Does this hold true? I’m concerned that Joseph Daniel (and other late career hitters) may suffer permanent increases in these %.

Matt Wilkes
9 months ago

It’s an interesting theory. FanGraphs did some research on it a while back and found that O-Swing% didn’t change much with age.

But it’s from 2012, so it may be worth looking into again!

Jefferson Green
Jefferson Green
9 months ago
Reply to  Matt Korte

Matt and Matt – thanks! Looks like older players’ slower bats get beat a little more often on pitches in the zone (and out of the zone), but their wisdom helps them lay off a few more pitches out of the zone. Interesting. Votto may have a better chance at some rebound than I thought.

Steve Mancuso
9 months ago

This has always been part of the case that Joey Votto’s core batting skills should be less susceptible to aging. On the other hand, I’ve seen a few players (Scott Rolen and Brandon Phillips come to mind) where it seemed like they compensated for slowing reflexes by starting their swing earlier. Swinging earlier means they can’t wait as long to see where the pitch is and end up swinging at more pitches outside the zone.

Jefferson Green
Jefferson Green
9 months ago
Reply to  Matt Korte

This is mostly eyeball test kind of stuff (the Fangraphs data tends to back it up a little, but not so much as I would have thought), but it felt like the ball quit jumping off the bat for Rolen and Phillips; their power disappeared except on grooved mistake pitches. I was feeling the same way about JDV until the late season swing change. It seemed that the ball started jumping off his bat again. I sure hope it continues.