What’s Behind Dylan Cease’s Slow Start?

After falling within the divisional spherical of the playoffs final October, the San Diego Padres got here into 2025 once more counting themselves among the many anticipated contenders within the Nationwide League. The most important supply of that optimism was the numerous funding the group has made in its roster over the previous few seasons, which included the commerce acquisition of right-handed starter Dylan Stop from the White Sox earlier than the beginning of final season.

Whereas starter Nick Pivetta was their solely main roster addition, and there have been persistent rumors they had been exploring salary-shedding trades, together with of Stop, the Padres have began quick and are only a sport and a half behind the juggernaut Dodgers within the NL West standings as of Could 21.

The membership has gotten implausible work from Pivetta and Michael King in its rotation, however Stop has lagged behind these two after ten turns. Coming off a season when he completed fourth within the NL Cy Younger voting and offered a 3.47 ERA throughout 189 and ⅓ innings, Stop sits with a 4.50 ERA by way of his first 54 innings this season. Among the many 79 certified beginning pitchers so far, that mark ranks simply 67th.

In his platform season earlier than his first crack at free company, this most likely was not what Stop had in thoughts. Furthermore, if the Padres are going to hold round with the Dodgers, they’ll want Stop to pitch like a front-of-the-rotation starter.

Each Stop and the Padres can exhale, nonetheless, as a result of the information means that his tough begin to 2025 has little to do along with his ability and talent, and rather a lot to do with a run of rotten luck and a much less succesful protection enjoying behind him.

The Extra Issues Change…

In assessing what could be happening with Stop, I continuously double-checked my work as a result of seemingly all of the numbers I checked out had been nominally the identical as they usually have been. I gained’t drag you thru a complete set of charts, graphs, and tables, however I’ll present you some examples of a few of our favourite pitching metrics:

Putting batters out and avoiding giving them free passes and residential runs are the essential constructing blocks of efficient pitching. In every of these areas, plus a few of our Pitcher Checklist staples known as strike plus whiff fee and PLV, Stop is true in step with his previous work. The identical is true for the placement part of PLV.

Stop’s fielding impartial pitching (FIP) is 3.51, not that far off final yr’s 3.10 and ranked thirtieth. The 0.99 run hole between Stop’s ERA and FIP is the 4th-largest distinction in MLB this season.

Because the PLV consistency would recommend, there’s been no change in Stop’s velocity — he’s averaged slightly below 97 mph along with his four-seamer, identical to up to now.

By way of pitch combine, he has turned to his slider extra usually this season. He used it 43% of the time final season, and it was the one most respected pitch within the sport by run worth (25 cumulative pitcher runs, per Statcast). This season, he’s thrown it 49% of the time, and the elevated deployment hasn’t diminished its effectiveness. The pitch has returned 5 runs and generated a 43.1% whiff fee.

If we need to squint to search out variations, we will argue that the shapes of Stop’s four-seamer and slider, which comprise virtually 85% of his pitches, have modified barely. His four-seamer has a contact extra arm-side motion and somewhat extra vertical motion, whereas his slider has a contact much less vertical and glove-side motion. Stop has acknowledged working by way of some mechanical changes early this season. Nonetheless, although, neither of these adjustments appears exterior the traditional variation, and the pitches are little modified in effectiveness, particularly for drawing whiffs and suppressing contact high quality.

Balls in Play and Sequencing

The largest factor that stands out in Stop’s information is his luck on batted balls and stranding base runners. Craig Edwards, previously of FanGraphs, wrote a chunk again in 2019 that confirmed that about 75% of the distinction between a pitcher’s ERA and FIP may be defined by batting common on balls in play (BABIP) and strand fee (LOB%). Once we look into these for Stop, we discover that the 2025 season, thus far, has been a problem in these two classes:

That 67.0% left on base proportion could be his lowest strand fee as a giant leaguer. His .301 BABIP is a contact elevated, despite the fact that it’s come down over the previous couple of begins. If it held for the remainder of the season, it might be the best his ultimate season in Chicago when his 4.58 ERA was 86 factors above his 3.72 FIP. Within the context of the remainder of the league, his strand fee is 73rd out of 79, and his BABIP is 62nd.

Because the strand fee suggests, that misfortune has been exacerbated additional as a result of a lot of it has occurred when there have been runners on base:

I’ll level out right here that 5 of the 7 dwelling runs that Stop has allowed this season have include the bases empty, which has helped stop this from being worse. However he’s been victimized by BABIPs nicely north of .400 when runners have been on base and in scoring place.

It’s honest to marvel then if Stop has allowed extra or more durable contact when he has been compelled to work from the stretch, however the information doesn’t reveal that to be the case.

He has allowed a median exit velocity of 89 mph with the bases empty, and 87.6 mph and 89.8 mph with runners on and in scoring place, respectively. He’s drawn a whiff on 27.8% and 31.8% of opponent swings with runners on and in scoring place, that are loads sturdy, albeit barely beneath the 35.1% he’s gotten with the bases empty.

Defensive Shuffling

Some measure of that is attributable to the work of the Padres’ protection. Final season, Statcast had San Diego as a roughly common defensive membership, ranked fifteenth with 2 runs prevented and a couple of outs above common as a bunch. Final winter, the Padres selected to let shortstop Ha-Seong Kim, a robust defender, go away in free company. The domino impact included transferring Xander Bogaerts and Jake Cronenworth up the defensive spectrum to shortstop and second base. Luis Arraez, who primarily DH’d final season, grew to become their most ceaselessly used first baseman.

The early collective returns on that shuffling haven’t been superb, regardless of Bogaerts holding his personal at shortstop. The group is presently twenty third in OAA, and first base (-3 OAA) and second base (-8 OAA) have been weak spots.

Stop has been significantly affected by these adjustments on the infield. The infielders behind Stop have accrued -3 OAA and transformed solely 64% of their defensive alternatives when he’s been on the bump, a 5% delta from the estimated 69% success fee of these alternatives. That OAA determine is close to the very backside of the 224 pitchers on the Statcast OAA leaderboard.

Going Ahead

So it seems that Stop’s stuff is nearly as good as ever and that he’s simply been hit by some unhealthy luck and unlucky timing to start out this season. Whereas I wouldn’t guess on the Padres’ protection enhancing considerably behind him, his batted ball and sequencing luck ought to normalize because the season progresses, and Stop’s top-line numbers ought to begin to look extra like they often do as he will get extra innings that blunt the consequences a few of his tough early season begins have on his seasonal numbers. In his final three begins, Stop has labored into the seventh inning in every and allowed a complete of 6 runs whereas putting out 25 batters and strolling 4. If these are any indication, the buy-low window could be closing shortly.

Photograph courtesy of Icon Sportswire | Tailored by Aaron Polcare (@abeardoesart on Bluesky and X)