I’m going to dive into blogging here and see where it goes. Sometimes, as a writer, the hardest thing is to come up with an idea that’s worth writing about and that people will actually be interested to read. I expect that to be my struggle, but I’ve got what I think will be an interesting series to kick things off, and maybe that will be the extent of my contributions. Time will tell.
In any case, nobody wants to read about me. You want to see what information you can glean about our Twins. Given the rampant discussions on Twitter and on various blogs regarding the state of the Twins’ pitching staff, I thought it would be interesting to do a series on the numbers underlying the starters currently projected to be in the mix for the Twins.
While I’m sure others will make starts this season, here are the guys I’m hoping to work my way through for this series:
By way of framing the series, I think there are pretty clearly three different groups. The known (but in some cases misunderstood) quantities, the new veterans, and the prospects.
When the season starts, we know Pineda and Hill will not be in the rotation, and we know Berrios, Odorizzi, and Bailey will be (barring injury, of course). That being the case, I decided to start off by diving into the three prospects (a term I’m using loosely, given the MLB experience they got last year), starting with Dobnak.
A common question we hear, read, and think to ourselves as we are trying to fall asleep: “Can Randy Dobnak be a key piece of a successful playoff run?” I can cut to the chase and just say the answer is yes, but if you want to know why, go ahead and keep reading the words.
Let’s start by looking at Dobnak’s surface-level stats:
- 28.1 IP – lots and lots of caveats about the small sample
- 7.31 K/9 – not inspiring, but we will need to take a look at his swinging strike rates
- 1.59 BB/9 – elite, but let’s see how often he’s really in the strike zone
- 1.59 ERA – wow, but a lot of this depends on the above
- 2.90 FIP – also wow
- 3.77 xFIP – still wow, but we will need to look into his batted ball tendencies because 0.32 HR/9 is the reason for the jump from his FIP to his xFIP.
Okay, so we have a few things to dive into:
- Swinging Strike Rates, which are generally highly correlated to K/9
- Zone Percentage, which is highly correlated to BB/9
- Batted Ball Tendencies, which are going to be a bit more difficult to use to extrapolate, given the small sample.
Getting hitters to swing and miss, and throwing strikes are generally skills the pitcher possesses (or does not), while the results – K/9, BB/9, HR/9, etc. Fluctuate due to randomness, umpire tendencies, opponents’ skill, etc. (esp in small samples).
Here’s what we see for Dobnak on those plate discipline skills:
- 43.8% of his pitches were in the strike zone
- 12.9% of his pitches resulted in a swinging strike
Putting those numbers into context, 61 pitchers qualified for the ERA title last season, so the median pitcher would be the one whose result was 31st among qualified starters. For swinging strike, it turns out that is a couple of familiar names: Jose Berrios and Homer Bailey at 10.8 percent. Looking at zone percentage, there is a three way tie among Jeff Smardzija, Mike Soroka, and Bailey again at 42.6 percent (a bit of a preview of the Bailey post. Hmm). By now you’ve surely noticed that Dobnak’s numbers were markedly above the median.
In fact, his zone percentage of 43.8% would have tied him with Zach Eflin for 20th among all qualified starting pitchers, just a tick below Noah Syndergaard at 43.9 percent. His swinging strike rate of 12.9% puts him in a three way tie with Charlie Morton and Clayton Kershaw, who were tied for 14th among qualified starters. Obviously good company.
It gets better. If you look at qualified starters who posted at least a 12.9% swinging strike rate combined with a 43.9% zone percentage – that rare combination of being in the zone and missing bats – here is the list you get for 2019:
- Gerrit Cole – 16.8%/45.2%
- Max Scherzer – 16.4%/45.6%
- Justin Verlander – 16.1%/45.2%
- Lucas Giolito – 15%/47.2%
- Yu Darvish – 13.4%/44.5%
- Charlie Morton – 12.9%/45.1%
- Clayton Kershaw
- German Marquez
- Lance Lynn
- Noah Syndergaard
- Trevor Bauer
- Walker Buehler
Does this mean Dobnak is in the company of these elite aces? Of course not. What it does suggest, though, is that his success was not a fluke. He displayed an elite combination of skills in missing bats (which generates strikeouts) and living in the strike zone (which prevents walks). This suggests that he has considerable upside. He also threw essentially a major league innings load last year – compiling more than 160 innings across 4 levels from High A to the majors. This suggests he’s capable of providing the Twins with volume as well as quality, something that is not always the case for prospect pitchers.
There are reasons to be worried, though. The difference between Dobnak’s FIP and his xFIP was driven by an unsustainably low 5.3% HR/FB rate. The lowest HR/FB rate among qualified starters was 9.3%, and given Dobnak’s 42.5% hard hit rate, it’s safe to assume more of those fly balls will reach the seats going forward. That said, if he regresses to the mean in HR/9 and posts 150 innings with a sub-4.00 ERA, that’s obviously a serviceable starting pitcher. And, given that FIP and xFIP were driven by his 7.31 K/9, if those swinging strikes turn that into a 9.00+ K/9, he has considerable upside to deliver a lower ERA.