At the start of the 2023 MLB Season, fans expected pitcher Jacob deGrom to continue his pitching dominance in the American League after signing a five-year, $185 million contract with the Texas Rangers. Unfortunately for Rangers fans, deGrom's greatest nemesis followed him to the Lone Star State; injuries. In his April 28 start against the New York Yankees, deGrom exited the game early with an elbow injury that would later require Tommy John surgery, ending his 2023 campaign.

However, the Rangers didn't need to hit the panic button, as seasoned veteran Nathan Eovaldi has surprisingly emerged as the ace of a pitching staff that has propelled the Rangers to first place in the highly competitive American League West division.

The 12-year vet has been at his best in recent years, coming off of a 4th-place Cy Young finish in 2021 with the Red Sox and a solid 2022 campaign hindered by recurring injuries. However, Eovaldi's first Rangers stint has been the best start to a season of his career, as his scorching hot month of May saw him post four wins and one no-decision to the tune of a 0.97 earned run average (ERA) and a 0.86 WHIP, both astounding numbers. The potential flashed in Boston, but nobody expected Eovaldi to put up Pedro Martinez-esque numbers at this point in the season.

To put it simply, Eovaldi's pitch mix seem to get better with his age. He has been excelling at inducing ground ball contact and striking out batters at a higher rate than his career averages.

First, come the groundballs.

Eovaldi's trademark as a pitcher has always been inducing weak, groundball contact that allows the defense to make easy plays. Eovaldi's success this year can be attributed to increases in groundball contact rate. In his previous years with Boston, hitters were making groundball contact off of him about 45% of the time, a respectable rate considering the injuries the starter dealt with. However, at this point in the season, Eovaldi has increased his groundball contact rate to 52%, meaning that almost half of the batters he faces in a game create easy groundball plays for outs. This effectively allows Eovaldi to power through innings and avoid extra-base hits by keeping the ball out of the air. While he has given up some runs on the year thus far, batters are only barreling up the ball 4.7% of the time against Eovaldi, meaning that hitters cannot consistently make good contact on the ball.

To delve further into the numbers, according to Eovaldi's BaseballSavant page, the veteran relies on five pitches: A four-seam fastball, split-finger fastball, curveball, cutter, and a slider. The average launch angle for contact on each of these pitches is less than 10 degrees, which translates directly into groundballs. The most effective of the latter is his split-finger fastball, which on average produces contact at a launch angle of approximately -4 degrees, a remarkable statistic. The official MLB website officially designates that balls put into play with a launch angle of 10 degrees or less are classified as groundballs, which essentially means that all five of Eovaldi's pitches consistently produce groundballs on balls put into play. Combine consistent groundball production from a starter with a borderline elite defensive Ranger infield, and you have the recipe for easy outs and the key to Eovaldi's success on the mound.

And those numbers mentioned above only account for when hitters make contact with the ball.

Eovaldi's strikeout rates have increased this season, as he is striking out 25% of the batters he faces in his starts, an excellent margin for a groundball pitcher. This can be attributed to massive improvements on his cutter and four-seam fastball. Last year, batters whiffed on Eovaldi's cutter and four-seam fastball 10.1% and 16.3% of the time respectively. However, following slight increases in pitch velocity for the 2023 season, batters are now whiffing on those pitches 24.3% and 20% of the time respectively. While Eovaldi's split-finger and curveball were already effective strikeout pitches, the increased whiff percentages on these pitches give him a third and fourth putaway pitch, as the increased velocity has proven to make these pitches harder to hit, and has certainly caused the increase in his strikeout rate this year.

With Eovaldi’s improvements on his pitches, he now acts as a double-edged sword who can be a power pitcher and rack up strikeouts, or a pitch-to-contact pitcher who can continuously create easy outs for his defense. It’s no surprise that Bruce Bochy continues to have Eovaldi at the top of the rotation following deGrom’s injury.

Eovaldi currently headlines a rotation of Jon Gray, Martin Perez, Andrew Heaney, and Dane Dunning. While Perez was an all-star last year, and Gray has looked to be a promising pitcher, Heaney and Dunning are too inconsistent to be cornerstones in this rotation. Eovaldi will have to keep up his production and take on high workloads for the Rangers to preserve their lead in the American League West, especially given his injury history over the last couple of years. Whether he is up for the task or not, only time can tell.

It's hard to say if Eovaldi can continue this incredible production throughout the rest of the season. However, fans should expect him to be a representative for the American League in the All-Star Game in July and be in the running for the Cy Young Award for this season, as he continues to dazzle fans as the unexpected ace of a surprising Texas Rangers squad.