ERA Lie Detector: Finding 2019 Underachievers with SIERA (Part 2)

Nicklaus Gaut further evaluates starting pitchers who could see positive ERA regression in 2020 fantasy baseball. based on last year's SIERA metric. These SP could be undervalued draft targets and sleepers.

Welcome back RotoBallers to my Lie Detector mini-series (you can read part one here). Skills-Interactive ERA (or SIERA) has been around since 2011 when it was introduced at Baseball Prospectus by Matt Swartz and Eric Seidman before moving to its current home at Fangraphs. Much like xFIP, SIERA attempts to quantify the skills that underpin a pitcher's ERA, albeit in a different manner. Although technically a backward-looking evaluator,  SIERA is slightly more predictive than xFIP in terms of the following year's ERA and most gets at the how and why of a pitcher's success.

FIP and xFIP generally ignore balls in play, focusing on only the things that pitchers can directly control; strikeouts, walks/HBP, and home runs. SIERA tries to take into account how specific skills (strikeouts, walks, ground balls) interact with each other in order to help pitchers limit runs. Strikeouts are even more valuable in SIERA, as high-K pitchers induce more weak contact, thereby running lower BABIPs and HR/FB%. Walks are bad but not as bad if you don't allow many of them, as they have a lesser chance to hurt you. The more groundballs you allow, the easier they are to field and the more double-play opportunities you'll have.

Essentially, instead of giving "flat-rates" for different skills, SIERA weights them, moving up the skills of pitchers who have high strikeout- or groundball-rates, or low walk-rates. While SIERA is not the "final word" in ERA evaluators (as different evaluators have strengths in different areas), it is quite sticky in terms of the following year's ERA. After previously looking at pitchers who had a higher SIERA than ERA, let's move to the flip side. We'll start today by looking at three pitchers who put up a lower SIERA than ERA in 2019, and judge whether they are worth the draft prices they are currently fetching.

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Largest ERA Underachievers in 2019

Looking at starting pitchers in the top-300 of ADP in NFBC leagues, there were just 20 players who had a lower SIERA than ERA in 2019. For sake of consistency, I'll be using dollar values derived via the Fangraphs auction calculator for 5x5 standard 12-team leagues.

Dinelson Lamet, San Diego Padres

2019: 4.07 ERA, 3.61 SIERA (0.73 run differential)

Returning for the end of 2019 after missing all of 2018 recovering from Tommy John surgery, Lamet got right back to business by striking out fools with extreme prejudice. Boasting a 33.6% K-rate over 73 innings, Lamet reminded everyone why he was a popular breakout pick before his surgery, using high-90s heat and a wipeout slider to leave hitters befuddled.

Goodnight, sweet Ronald:

While his 4.07 ERA wasn't anything to write home about, Lamet got much better marks from his evaluators:

Remember that FIP (as well as xERA, which is xwOBA translated to an ERA-scale) correlate most to in-season ERA, giving the best picture of how much a pitcher's ERA was "earned". SIERA and xFIP, on the other hand, are the most predictive in terms of the following year's ERA.

If qualified, Lamet's 3.44 xFIP and 3.61 SIERA would've both been the 15th-lowest among starters in 2019, with a 24.0% K-BB% finishing 11th-highest. Those numbers put the 27-year-old with elite company but will hitters start to figure out the 27-year-old righthander in 2020?

Does He Need Another Pitch?

While Lamet's talent wasn't a secret prior to his 2018 surgery, it seemed his limited arsenal would eventually doom him to the bullpen, throwing nothing but a two- and four-seam fastball, along with the slidepiece. Without something else to show hitters in 2017, his numbers got progressively worse the deeper he went into games. Lamet had a 3.68 FIP and .261 wOBA the first time through the order but a 6.77 FIP and .410 wOBA the third time through.

Even though he carries premium velocity, Lamet's fastballs don't do much moving, with both pitches having below-average movement on both planes. And no matter how nasty the slider is, batters will figure you out as the game goes on if you don't have other offerings. Lamet also had particular problems against left-handers, lacking a breaking ball that moved away from them. The other-sided batters teed off for a .364 wOBA against him in 2017, compared to the .239 wOBA that right-handers managed.

However, Lamet may have already added another pitch, albeit more stealthily, by breaking his slider into two pitches. He still had the big sweeper that we saw strikeout Ronald Acuna Jr. earlier but another version is tighter and moves more like a cutter. As Ben Clemens detailed on Fangraphs, Lamet's "slider" has a large spread on horizontal movement, moving anywhere from 3.4 to 6.5 inches to the glove side.

According to Baseball Savant, Lamet has a slider and curveball but he also has everywhere in between, in reality. These pitches all have roughly the same speed and spin but move in dramatically different ways, making classifying his pitches as difficult as hitting them. Fortunately, this just gave me more reasons to look at pitch videos.

Here's Ben Gamel getting tied up by one of Lamet's 88 mph "curveballs":

And here is Brian McCann taking an 83 mph curveball the "right way":

Lamet's pitches may be hard to analyze individually but his overall performance isn't. No matter how you slice them up, Lamet was nastier than he's ever been in 2019, with his slider carrying a 27.8% SwStr% (that was tied for with Patrick Corbin for the highest among starters) and the "curveball" having a 21.8% SwStr% that was second only to Blake Snell.

2020 Fantasy Outlook

Lamet currently has a 119 ADP in NFBC leagues that has risen only slightly from the 125 ADP he had in January, being taken after Lance Lynn (118), Mike Soroka (107), Corey Kluber (102), and Frankie Montas (100). Of those four pitchers taken just before him, Lamet is most analogous to Montas, both in upside and risk. Much like Montas, we saw a different and better version of Lamet in 2019 but in a sample of less than 100 IP. Montas succeeded on the back of a new split-finger, while Lamet added different versions to his slider. Do you believe in the changes, or not?

I believe. Lamet's fastball(s) have premium velocity but are still entirely too hittable, so if he was still surviving on just them and the slider, the bullpen reaper would surely be lurking. But we see saw a whole new Lamet in regards to the movement and shape of his breaking balls and I don't believe that was an accident.

Consequentially, I have to believe that 2020 will only bring more of the same and his 3.61 SIERA makes me hopeful for an ERA in the 3.75 area. Paired with an elite K-BB%, that gives Lamet top-15 upside that's far from the SP 31 that he's currently being drafted at.

Carlos Carrasco, Cleveland Indians

2019: 5.29 ERA, 3.53 SIERA (1.76 run differential)

Putting all baseball aside, fantasy and otherwise, Carrasco's leukemia diagnosis last July was an absolute punch in the gut. Somehow, Carrasco missed just two months and returned to pitch in the bullpen for all of September. His numbers from above are from his overall performance and when you include a 3.50 xFIP, .354 BABIP, and 22.2% HR/FB, it seems apparent that Carrasco was rather unlucky on the field in 2019.

The skills still seem to be there; Carrasco had a 28.1% K-rate that was right in line with previous seasons and his already stellar walk-rate dropped a few points more, finishing with a career-low 4.7% BB%. Nothing seemed out of order with his pitch pix, compared to previous years, besides his curveball being basically dropped after having been pared back from 18% usage in 2017 to 7% usage in 2018. And his velocity and movement were also basically the same as in the past. So what gave?

For one, his changeup went from an elite weapon to left-handers (0.0% Brl% in 2017, 1.7% Brl% in 2018) to immensely hittable, with a 17.9% Brl% and .501 wOBAcon in 2019. What's interesting is that is still got a lot of whiffs, with a 22.8% SwStr% that wasn't that far down from the 24.4% SwStr% that it garnered in 2018.

Change and Release

When I see a pitch go from great to bad, I immediately check to see if the release points have changed. Inconsistent release points can make for inconsistent performance and we have seen a change moving from 2017 to 2019:

The differences aren't dramatic and Carrasco has actually tightened things up, as far as consistency goes. However, the release has changed, both horizontally:

And vertically:

Looking at the pitch profile, the vertical movement has stayed virtually the same over the last three year but things have gotten progressively more static on the horizontal plane. Carrasco's movement on the changeup has always been below-average compared to the rest of the league but has now decreased two years in a row, going from 12.4 inches in 2017 (14% less than average), to 10.7 inches in 2018 (26% less), to 10.0 inches in 2019 (30% less).

And while Carrasco only had a 1.7% Brl% against the changeup in 2018, the quality of contact had gone up dramatically after 2017's .176 wOBAcon, with the changeup allowing a .327 wOBAcon to lefties in 2018.

Looking at the location heat maps, the changeup has crept further inside since 2017, finishing mostly dead-red in 2019:

2020 Fantasy Outlook

If Cookie doesn't want to crumble in 2020, getting his changeup back on point may be the key. When it's right, it gives Carrasco a devastating complement to a slider that had a 40.7% K-rate in 2019. Having two pitches to throw to left-handers that break both directions is a boon to right-handed pitchers. But the more changes you hang, the more changes get hung in the seats:

It may feel gross but we also must consider Carrasco's health. If this were a normal season, I'd be taking his health at face value. Unfortunately, we're in the midst of a pandemic with a disease that can be most devastating to those with compromised immune systems. And new findings are coming forth that COVID can move from a respiratory disease to a blood-borne one by affecting the endothelial cells that line the inside of blood vessels. I'm no scientist and won't attempt to put myself in Carrasco's shoes but this must be scary news for someone who has recently had blood cancer.

The MLBPA recently put forth their proposal for resuming play in 2020 and it included specific language for players, both high-risk and not, being able to opt-out due to health concerns. I personally will blame zero players who wish to not play this season, whether out of concern for themselves or their family members - and that goes 1000x for Carrasco.

As far as performance and fantasy value in 2020, I have few concerns about Carrasco. But the betting man inside of me can't guarantee that he plays in 2020. My fingers only stay crossed for his health.

Matthew Boyd, Detroit Tigers

2019: 4.56 ERA, 3.61 SIERA (0.95 run differential)

The numbers don't lie; Boyd had a terrible second half in 2019:

Woof. The best news about Boyd's second half was that while his strikeout rate dropped to 27.9% from 32.0%, it was still a giant step forward from his rates of whiffery in the past. In his first three years in the majors, Boyd's K-rate resided in the upper-teens, with a 22.4% K-rate in 2018 representing his previous career-high. Boyd posted an overall 30.2% K-rate in 2020 on the back on an improved slider, with the pitch jumping from a 15.7% SwStr% and 33.6% K-rate in 2018 to a 19.6% SwStr% and 41.5% K-rate in 2019.

Boyd has a nasty slider at the bottom of the zone and a high-spin four-seam that he can use to attack the top of the zone. This is a formula we've seen succeed much as of late and could be the key to the Tiger left-hander being a fantasy stud in 2020. However, the home run issues will need to be corrected, as Boyd's 1.89 HR/9 was the highest among qualified starters in 2019. His 18.2% HR/FB was a career-high, though, and came after three-straight years with marks between 10.6% and 12.9%.

2020 Fantasy Outlook

According to the Fangraphs auction calculator, Boyd finished as SP 85 and currently has a 157 ADP in NFBC leagues as the 44th starting pitcher off the board. Coming off a year where he posted career-bests in both K-rate (30.2%) and walk-rate (6.3%), Boyd could be in for a full breakout in 2020. Wins may be hard to come by playing for a substandard Tigers team, but Detroit did upgrade their offense, and Boyd is being projected for around 10 wins.

Double-digit wins with a 30% K-rate is nothing to sneeze at and Boyd is currently going after the likes of Madison Bumgarner, Kyle Hendricks, and Eduardo Rodriguez. Give me the ceiling of Boyd over the limited upsides of the aforementioned veterans.

Other Notables

Andrew Heaney, Los Angeles Angels

The oft-injured Heaney missed the first two months of 2019 with elbow inflammation and hit the IL again in July, this time for shoulder inflammation. While he was successful upon his return, posting a 1.82 ERA over four starts and 24.1 IP, but got blown up in September, albeit while facing some of baseball's best offenses. Heaney had a 7.66 ERA in the month, twice giving up six runs to the Yankees and Rays.

Heaney may be perennially injured but he's also perennially seductive, given the promise of his strikeout ability. Finishing with a 28.8% K-rate, Heaney does it with a nasty curveball that had a 19.3% SwStr% and 40.2% K-rate in 2019. The swinging-strike rate was on par with previous years, while a 7.9% Brl% was a career-low. However, the .477 wOBAcon and .415 xwOBAcon against the curve were both career highs and the 50.8% Weak% was a career-low.

The best thing about Heany is the low risk of his 196 ADP combined with a shorter season giving him a better chance to actually pitch the whole year. Heaney will also have the backing of a Trout-led offense that recently added Anthony Rendon. If you're hunting wins and strikeouts later in the draft, then Heaney could be your man, but beware that he'll always be a ratio-bomb waiting to happen.

Dylan Cease, Chicago White Sox

A top prospect for the Southsiders, Cease's rookie year didn't exactly go as planned, with the right-hander posting a 5.79 ERA and 1.55 WHIP. His 10.7% walk-rate wasn't inspiring either but Cease did have a solid 24.9% K-rate, striking out 81 batters in 73 innings. And following a disastrous 6.92 ERA over his first two months in the majors, Cease finished strong in September with a 3.00 ERA and 31.8% K-rate in four starts.

With a 277 ADP in NFBC leagues, there isn't much risk in drafting Cease. Either his September success carries over and gives him top-40 upside, or he flails and you punt him right back to the waiver wire. I'm happy to draft him in deeper leagues but I'll be very wary starting him from the jump if he has some tough matchups early on.

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