Statcast Pitcher Risers/Fallers - Fastball Quality (Week 12)

Welcome back to RotoBaller's series using Statcast to extrapolate, dig into, and commiserate over data to examine pitching performances. The weekly series will be dynamic as we fine-tune our findings and enlighten ourselves on the information and tools at our disposal.

Chicks dig the fastball. At least that's how this pitching-friendly column remembers the classic commercial. But seriously, fastballs are critical to a pitcher. Most rely on it for over 50% of their pitches. At worst it's a table-setter and at best it's a knockout punch. Since its efficacy is so important, fastballs likely impact the remaining pitch selection for a given plate appearance.

This week, we'll look at fastball effectiveness on two metrics, expected wOBA (xwOBA) and contact quality. The median fastball xwOBA for a pitcher is .367. For contact quality, the best pitchers like Max Scherzer, Justin Verlander and Jacob deGrom surrender well-hit fastballs at a 20-22% clip. The worst pitchers have a well-hit fastball rate north of 30%. Looking at these two criteria will determine our risers and fallers for Week 12.

Bound to Pop

All stats as of June 18 for 112 pitchers that have thrown over 1000 pitches. Well-hit balls include all batted-ball results not classified as poor/weak by MLB.com.

Vince Velasquez, Philadelphia Phillies (5-7, 4.74 ERA, 1.30 WHIP, 10.82 K/9)

Vince Velasquez made an early appearance in the Statcast series and he finds himself back in the discussion nine weeks later. He's given up well-hit fastballs at a solid 21.8% and his xwOBA of .306 is 17th-best. Prior to a 10-run implosion on June 8, Velasquez had pitched well in 6-of-7 outings. Dependability has been an issue, with seven quality starts mixed in with five clunkers through 14 starts.

Velasquez has leveraged his mid-90s fastball to generate a strong whiff percentage around 15%. More importantly, he's refined his slider to an excellent normalized pitch value of 1.43 and finally developed a coveted tertiary pitch, mixing in a useful changeup for the first time in his career. Velasquez has also upped his sinker usage from 4% in April to 17% in June. With a loaded arsenal in 2018, Velasquez has been able to peel back on the four-seamer, enhancing its overall effectiveness. Unfortunately, Velasquez has been reluctant to abandon his awful curveball (.900 opponent slugging in June), which he still serves up 19% of pitches.

Despite consistency being his Achilles heel, Velasquez is a worthwhile weekly streamer for the strikeouts and ongoing evolution of his repertoire. For what it's worth, he's significantly better away (2.79 ERA) than at home (6.88).

Tyler Mahle, Cincinnati Reds (5-6, 3.96 ERA, 1.37 WHIP, 8.16 K/9)

Rookie Tyler Mahle has gradually improved as the season's progressed, riding a 1.10 ERA and 1.22 WHIP through three June starts. Mahle ranks just behind Velasquez with a .312 xwOBA, giving up well-hit contact on 22.0% of heaters.

Mahle is a straightforward three-pitch pony, utilizing his fastball on 68% of pitches. It's also been his strongest pitch, with a sub-.300 BAA and a whiff percentage of 11%. Mahle's chief improvement in June has been his slider. In April, batters were whiffing, but they also clocked a healthy .308 ISO off the pitch. Mahle's flipped the script in June, pitching to contact with much better results (.000 ISO).

Mahle's endured his share of speedbumps in 2018. A 41.6% Hard%, 2.43 K/BB and 4.73 FIP confirm his downside. But he appears to be making the right adjustments throughout the season with encouraging results. Minimally owned, Mahle's worth a test drive over his next handful of starts. If he keeps capitalizing on the fastball and maintains his slider touch, his fantasy value could be upgraded for longer term.

Other possible risers: Ross Stripling (LAD, .260 fastball xwOBA), Eduardo Rodriguez (BOS, .285), Miles Mikolas (STL, .304)

Due to Drop

Zack Godley, Arizona Diamondbacks (7-5, 4.77 ERA, 1.51 WHIP, 9.08 K/9)

The first fantasy relevant player with a poor fastball xwOBA is Zack Godley in ninth-worst position (.432), ceding well-hit fastballs at 29.2%. However, unlike most pitchers, Godley isn't heavily reliant on a fastball, using his cutter just 23% of pitches. While not having a traditional four-seamer isn't a problem outright, it is when your substitute is alarmingly losing velocity.

Godley entered the league with a cutter hovering around 91-92 MPH. This season, it's plummeted to 88.8 MPH. The deceleration may not seem material on the surface, but line drives on his cutter have increased from 28% to 34% year-over-year. Opponent slugging has lingered above .429 all season, with an unsightly .643 in June.

Godley hasn't been good in 2018, but his ownership remains stubbornly high. He does have strikeout appeal, and his BABIP (.318) and LOB% (71.3%) suggest some fortunes may turn his way. But his batted-ball metrics are not encouraging, and for someone that can barely touch 90 MPH on the radar gun, selling at a discount appears wiser than holding and hoping.

Dylan Bundy, Baltimore Orioles (5-7, 3.81 ERA, 1.19 WHIP, 10.04 K/9)

Dylan Bundy, on the other hand, loves his heater. He's increased its usage from the low-40% in April to 56% in June. His returns in June have been marvelous through three starts (1.71 ERA, 0.86 ERA), but that doesn't diminish the fact that his fastball suffers from the 10th-worst xwOBA (.430) and a 34.5% well-hit rate.

Bundy is currently on a career-best strikeout pace, but it's not from the fastball. His four-seamer is generating a whiff percentage below 10% and the punch outs are mostly coming from his slider and changeup. Then why the focus on the heater? Possibly because despite the strikeouts, the only pitch that grades positively for Bundy is his slider. While he generates swings-and-misses for the changeup, it's mashed upon contact.

It makes sense for Bundy to use the fastball to setup his knockout slider, but overemphasizing it seems counterintuitive. We lowlighted his unflattering off-speed pitch, but results from the heater aren't much better (30% LD%, .450 SLG). With his strikeouts down in June (7.29 K/9), the fastball proportion is arguably to blame. Whether the pitch selection is intentional, mechanical or psychological, Bundy's spectacular June doesn't appear supported by strong fundamentals.

Other possible fallers: Jake Junis (KC, .451 fastball xwOBA), Aaron Sanchez (TOR, .427), Luis Castillo (CIN, .426)

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