Welcome back to Rotoballer’s series using Statcast to extrapolate, dig into, and commiserate over data to examine pitching performances. The weekly series utilizes the myriad tools and information provided by Statcast to pinpoint encouraging and worrying trends underneath the hood of headline numbers.
Well, we’ve reached the endgame. Week 26 marks the last of the MLB regular season and the conclusion of season-long fantasy leagues. We’ve delved into various advanced metrics this year to pick risers and fallers. We’ll regard some picks with pride (German Marquez) and ‘fess up to the brutal calls (Sonny Gray). Nonetheless we hope you readers (our most valuable asset) found some useful tidbits along your fantasy journey.
For our finale, we’ll use xwOBA and wOBA variance to identify (very) early sleepers and fades for next year. Over the course of a season, a pitcher’s actual results (wOBA) and expected outcomes (xwOBA) should reach parity. Of our 144 qualified pitchers, the median difference is just -.014 year-to-date. So barring a structural issue with a pitcher’s individual makeup, a sustained gap between the two measures could indicate a highly fluky season.
Featured Promo: Want a free RotoBaller Premium Pass? Check out these sports betting promo offers from the top sportsbooks! All new sign-ups get a free bonus offer on their first deposit, and a free year of RotoBaller's Premium Pass for all sports ($450 value)! Sign Up Now!
Early 2019 Pops
All stats as of September 24 for pitchers with over 1500 pitches thrown in 2019. All ranking references via ESPN.
Ross Stripling, Los Angeles Dodgers (8-5, 2.84 ERA, 1.15 WHIP, 10.02 K/9)
Prior to suffering an injury in early August, Ross Stripling was a rising fantasy darling, toting a 2.62 ERA through 28 appearances (20 starts). Relegated to relief duties since his return, Stripling has become fantasy obsolete and fallen off the radar.
Early draft preppers should note Stripling leads all pitchers with a favorable .027 difference between his wOBA (.300) and xwOBA (.273). Considering the stellar numbers this season, he might be better next year. At 28 years old, Stripling could be considered a late bloomer but he does enjoy a 3.45 career ERA (3.59 FIP) across three seasons. His strikeout numbers have improved each year, highlighted by a spectacular 6.70 K/BB in 2018.
Stripling currently clocks in as SP90 in early 2019 projections which seems absurd. He pounds the strike zone (69.7% F-Strike%), induces weak ground balls (45% GB%, 83.0 MPH GB exit velocity) and has harnessed a potent curve to raise his whiff profile across the board. Take advantage of this blatant mispricing next year.
Nick Pivetta, Philadelphia Phillies (7-13, 4.58 ERA, 1.29 WHIP, 10.45 K/9)
After a rough major league debut in 2017, Nick Pivetta bounced back admirably to start the year, boasting a 3.26 ERA and 1.09 WHIP through two months. Things went sideways in June and July, but Pivetta is poised to finish the year on a promising note (3.93 September ERA).
Pivetta holds the fifth-widest margin of .019 between his wOBA (.318) and xwOBA (.299). He’s grown confidence in his curveball this year, using it 21% of pitches to parlay with a mid-90s heater and slider. The result of his newfound Uncle Charlie was a broad dip in opponent average, SLG and increased swings-and-misses. Continuing these positive trends could drop his ERA closer to the 3.71 FIP he’s registered this season.
Pivetta slots in as SP62, so while not as egregious as Stripling, he’s not a consideration in standard leagues. Pivetta is only 25 and improved in every relevant statistical measure in his sophomore campaign. Give me upside in late-round picks over predictable mediocrity (a la Jake Arrieta, Kyle Gibson) all day.
Other possible sleepers: CC Sabathia (NYY, .015 wOBA/xwOBA differential), Zach Eflin (PHI, .012), German Marquez (COL, .009)
Early 2019 Drops
Julio Teheran, Atlanta Braves (9-8, 4.03 ERA, 1.19 WHIP, 8.33 K/9)
Headlining our fantasy-relevant starters with an unfavorable wOBA/xwOBA variance is Julio Teheran. His -.039 differential is seventh-worse in our pitcher pool. Teheran has followed up a 2017 faceplant (4.49 ERA) with another disappointing performance in 2018.
While Teheran has shown a modest recovery in his strikeout figures, walks have been a growing bugaboo spiking from a 2.18 BB/9 in his 2013 rookie year to 4.35 this season. Declining velocity and a material uptick in Hard% to 37% are alarming trends. For a fly ball pitcher (41% FB%), a 93.7 MPH FB/LD exit velocity is an ominous premonition.
Teheran is positioned as SP51 in early rankings so he’s not popping off the draft board. But his ownership has remained stubbornly high across the past two pedestrian seasons. Teheran is only 27 but with six full years under his belt is a known commodity. He’s a durable innings-eater but possesses a skill set more useful in fantasy as a streamer than weekly starter.
David Price, Boston Red Sox (15-7, 3.53 ERA, 1.12 WHIP, 9.00 K/9)
David Price has continued his spectacular career in 2018, collecting double-digit victories for the ninth time out of ten. However, Price has been somewhat fortunate this year, logging a wOBA (.296) and xwOBA (.325) discrepancy of -.029.
The clashing actual and expected results may support a broader portrait of Price’s deteriorating skillset. His SwStr% (9.6%) and Swing% (47.4%) are at four-year lows. Inversely, contact rates have climbed to 79.8%. Price’s excellent second half (2.00 ERA, 0.90 WHIP) has wiped the memories for most fantasy managers of his nightmare numbers before the All-Star break (4.42 ERA, 1.25 WHIP).
Price is positioned as SP24 and 100 overall. He plays for a win-friendly squad and has demonstrated enough consistency to earn undisputed fantasy trust. But the discouraging trends, alarming split performances and declining velocity and pitch effectiveness could indicate Price is entering his twilight years. As the adage goes, better to get off the bandwagon early than late.
Other possible fades: Blake Snell (TB, -.037 wOBA/xwOBA differential), Jon Lester (-.035), Madison Bumgarner (-.033).