Tony Gonsolin Is the Latest Dodgers’ Starter To Dominate Hitters

Given their success over the past half-dozen years and the strength of their preseason projections, it’s no surprise to find the Dodgers owning the National League’s top record (37-20, .649) while continuing to hold the league’s highest Playoff Odds (98.4%) and highest odds of winning the World Series (15.5%). What’s unusual is that they’ve done it with Clayton Kershaw missing about half the season thus far and with both Walker Buehler and Julio Urías struggling to regain their front-of-the-rotation form. Instead it’s been Tyler Anderson and Tony Gonsolin — two pitchers we initially projected to throw fewer than 100 innings as starters — leading the way in a rotation that has the majors’ lowest ERA (2.65).

On Thursday, Anderson’s scoreless streak came to an end at 28 innings against the White Sox, thanks in part to a ball that parkour’d its way into becoming a triple, but so far this year, he’s ridden an improved changeup to unexpected success. The night before that, it was Gonsolin holding Chicago to one run over six innings while helping to halt a three-game losing streak, the Dodgers’ second within a nine-day span. In the process, the 28-year-old righty took over the official NL ERA lead, at least for the moment, via a 1.58 mark. He’s pitched 57 innings while the Dodgers have played 57 games, but he’ll slip below the qualifying threshold again before he next gets the ball.

Regardless, Gonsolin is showing signs of a breakout, and at the very least enjoying his longest sustained run of major league success. Though he’s pitched for the Dodgers for four seasons — and largely pitched very well, with a 2.48 ERA and 3.50 FIP in 199.1 innings — it’s been in fits and starts. The ninth-round 2016 pick out of St. Mary’s College of California debuted in the majors three years later but that year was yo-yoed between Los Angeles and Oklahoma City, totaling just six starts, five relief appearances, and 40 innings. In 2020, Gonsolin totaled eight starts, one relief appearance, 46.2 innings, and three times being optioned to the Dodgers’ alternate training site. Last year, he spent two separate stretches on the injured list due to recurring right shoulder inflammation, not debuting until June 9 and then spending all of August and part of September sidelined. He made a career-high 13 starts plus two relief appearances but finished with just 55.2 innings.

As noted before, this year Gonsolin has surpassed that total in just 11 starts, and part of the reason is that he’s pitched so well. Only once has he allowed more than two runs in a start; he yielded three against the Diamondbacks on April 26, only two of which were earned. A quick comparison between this year and last year:

Gonsolin has cut both his ERA and home run rate in half relative to last year; the latter ranks 10th in the league, his FIP and strikeout rate both 12th. Even though he’s punching out fewer batters relative to last year, he’s lowered his walk rate substantially and become more efficient, which has allowed manager Dave Roberts to loosen Gonsolin’s leash:

Despite being limited to a combined total of seven innings over the course of his first two starts as he ramped up his pitch count following the lockout-shortened spring training, Gonsolin is facing more batters per game than ever. He’s pitched six innings in each of his last five starts, that while holding batters to a .147/.193/.314 line and striking them out at a 28.4% clip. That’s downright dominant.

Gonsolin’s success this year owes something to the increased emphasis of his split-finger changeup, a pitch that’s currently averaging 83.4 mph, 9.8 mph slower than his four-seamer. He began working with the pitch in the spring of 2017 after being drafted the previous year; Joel Peralta, a former major league reliever working in the Dodgers’ front office, taught it to him. The pitch turned him from a hard-throwing relief prospect into a rotation candidate, and as Baseball Prospectus’ Jarrett Seidler recently illustrated, at the major league level, Gonsolin has improved the offering by gaining nearly a foot of vertical movement from 2019 (25 inches, using Statcast’s numbers) to ’22 (36.8 inches) while reducing its spin from an average of 1,998 rpm to 1,370 rpm in the same span.

Gonsolin threw the splitter a career-high 29.8% of the time in 2020, but he hadn’t increased the drop or decreased the spin significantly relative to the year before. Batters making contact with the pitch hit it for a .220 AVG and .390 SLG. He backed off of its usage somewhat last year while improving its shape, with very good results, and has now increased the pitch’s profile at the expense of his four-seam fastball, a pitch that has rarely been particularly effective for him at the major league level save for 2020, when he was pumping it at 95.1 mph, about two ticks faster than now.

Batters haven’t been able to do a damn thing with the splitter — or for that matter with either of his two breaking pitches — when making contact:

Among pitchers with at least 100 splitters thrown this season based on Statcast’s classifications (which may differ from those of Pitch Info and Sports Info Solutions), Gonsolin has the lowest wOBA allowed, and the second-lowest AVG and SLG allowed:

That’s pretty impressive. Batters are chasing Gonsolin’s splitter out of the zone a career-high 45% of the time, and while they’re making more contact than ever (73.1%, up from last year’s 58.6%), they’ve produced an average exit velocity of just 86.6 mph, a hard-hit rate of 26.6%, and a barrel rate of 2.2% — that’s a single barreled ball, a homer by the Phillies’ Garrett Stubbs on May 22.

Overall, Gonsolin has cut his barrel rate from last year’s 7.1% to 5.6% (73rd percentile) and his hard-hit rate from 35% to 26.4% (97th percentile). His 2.56 xERA ranks in the 91st percentile and is over a full run lower than last year’s mark of 3.63. It’s an impressive start to the season that has helped the Dodgers maintain their usual perch despite their key injuries and slumps, and it may very well garner Gonsolin All-Star consideration.

However, given that Gonsolin threw just 68.1 innings last year between the majors and minors, and hasn’t topped 81.1 innings since 2018, we should expect the Dodgers to rein in his innings total at some point so as to keep him available in October. The pending returns of Kershaw from SI joint inflammation in his lower back and Andrew Heaney from shoulder inflammation should help, and at some point Danny Duffy and Dustin May could return from their respective surgeries (flexor tendon for the former, Tommy John for the latter) to start as well. How the Dodgers will piece it together is an issue for another day — the adage of never having too much pitching applies here. The names may change, but the Dodgers’ rotation will keep rolling.