xERA Agrees: The Pirates Rotation Needs Work

Following the season, Wilbur took a good look at the Pirates’ starting rotation options for 2022, and summarized things succinctly: “The bottom line is, the Pirates need to seriously pare down this list and add a few more guys to it. The amount of flotsam is stunning.”

Ben Cherington seems to agree, acquiring Jose Quintana and Zach Thompson, parting with Chad Kuhl, Steven Brault and Cody Ponce, and saying that he hopes to add to the rotation before all is said and done. 

That’s a good thing, because despite this handful of moves, the rotation remains one of the worst in baseball. 

That’s illustrated clearly by the Expected Earned Run Average (xERA) for the rotation candidates. Think of xERA as Fielding Independent Pitching (FIP) with Statcast’s quality of contact factored in. (The longer definition of xERA is here.) It gives you a better indication of how a pitcher should have performed, versus how they did perform (ERA). Unfortunately, xERA is only available in the majors, so we don’t have an apples-to-apples look at minor league pitching.

Let’s look at the rotation candidates who pitched in the majors last year (note a few small sample sizes):

Roansy Contreras 3.0 0.00 2.83 -2.83
Zach Thompson 75.0 3.24 3.71 -0.47
Connor Overton 15.1 4.70 4.12 0.58
Dillon Peters 26.2 3.71 4.48 -0.77
Max Kranick 38.2 6.28 4.54 1.74
JT Brubaker 124.1 5.36 4.60 0.76
Jose Quintana 63.0 6.43 5.09 1.34
Wil Crowe 116.2 5.48 5.26 0.22
Bryse Wilson 74.0 5.35 5.66 -0.31
Mitch Keller 100.2 6.17 5.70 0.47
Chase De Jong 43.2 5.77 6.44 -0.67
Miguel Yajure 15.0 8.40 8.85 -0.45

One would think Contreras could lock up a rotation spot, given the dreck surrounding him, but we wouldn’t advise placing a big bet on that. While the Pirates appear to be more aggressive with promotions under Cherington, Contreras has pitched only 6.2 innings above AA, which would be a convenient stat to highlight when demoting him.

Thompson will be at or near the top of the rotation, which should tell you all you need to know about the state of the staff. 

If Overton, Peters, or De Jong is in the rotation, then something has gone seriously wrong during the offseason. 

Any of Kranick, Brubaker, Crowe, and Keller could end up in the rotation or long relief or in Triple-A. All threw better than their ERAs indicated last year, especially Kranick and Brubaker (though they were still pretty ordinary), and with some changes, each could take meaningful steps forward.

Quintana is a favorite to be an opening week starter, even though he was better as a reliever last year … and really wasn’t all that inspiring in any capacity. 

Wilson is out of options and is a favorite to start the season in the rotation, despite a 5.66 xERA. (He also had xERAs of 6.48, 6.38 and 5.63 in small sample sizes in 2018-2020.)

Yajure is a bit like Contreras, without the pretty xERA. With the rotation options available today and his decent performance in Triple-A, he should compete for a spot with Brubaker, Kranick, Crowe and Keller.

If you absolutely had to make a projection, the opening day rotation might look something like this, barring another acquisition by Cherington:

  • Thompson: 3.71 xERA
  • Quintana: 5.09
  • Wilson: 5.66
  • Brubaker: 4.60
  • Keller: 5.70

Swap in Crowe or Kranick and things don’t look any better from an xERA perspective. xERA isn’t a perfect predictor of future success (or lack thereof), but it’s clear that pitching coach Oscar Marin has some work to do.

And if you are wishing the team had kept Kuhl, Brault or Ponce, their overall xERAs don’t indicate that they would have made much of a difference:

Chad Kuhl 80.1 4.82 4.79 0.03
Steven Brault 27.2 5.86 5.88 -0.02
Cody Ponce 38.1 7.04 5.16 1.88