An Optimistic Look at the Cubs Rotation
Today I want to optimistically look at the Cubs rotation. While there was a ton of hand wringing over trading Darvish, and letting Lester, Quintana and Chatwood walk, I am confident that Jed Hoyer's assembled rotation will be better in 2021 that what the Cubs 2020 rotation will do as a collective in 2021. First off, Jed Hoyer was the General Manager behind assembling a group of ERA leaders for the last six seasons. Here is where the Cubs have ranked in all of baseball in ERA during the competitive era:
2020: 7th
2019: 7th
2018: 3rd
2017: 8th
2016: 1st
2015: 3rd
Yes, that's what happened in the past, and does not guarantee what will happen in the future. But as Jed Hoyer was the GM of each of those teams, let's give him a little credit for being able to assemble a staff. Despite the lack of developed starting pitching prospects, Jed has made some savvy trades and solid free agent pickups to assemble good rotations year in and year out. He's got a great track record, and deserves some benefit of the doubt.

Rather than just celebrate the past, I've assembled a list of reasons to be optimistic about the six guys who figure to get the majority of the starts in 2021: Hendricks, Davies, Arrieta, Alzolay, Mills, and Williams. We can figure on Tyson Miller and Justin Steele maybe getting a start or two as well. As a group, it's decent on paper. Hendricks and Davies were as good as any 1-2 in baseball in 2020. The rest of the guys weren't quite as solid, but each has some upside. With a solid pitching coach and the pitch lab, we have to hope that some of these players have a chance to improve in 2021.
Kyle Hendricks:
He was 9th in Cy Young voting in 2020. Optimistically, I predict he'll break the top 10 in voting again in '21. Why? He continues to improve on his walk rate. In the last 4 years, Hendricks has cut half a walk per 9 innings off his rate. He led the league in fewest walks per 9 in 2020. He's continued to limit home runs to just 1 per 9 innings. Considering how all the other NL central teams focus on the long ball, I think he has a chance to continue to induce weak contact and keep cruising through lineups.
Kyle Hendricks does not get the respect he deserves. Among active leaders he is
5th in ERA+
7th in WHIP
13th in K/BB ratio
16th in FIP
11th in HR/9
Kyle Hendricks is an ace. He will be among the top 10 pitchers of this generation by the time he is done.
Zach Davies:
Davies had a lower ERA than Kyle Hendricks did in 2020. He cut his walks, and allowed nearly 2 fewer hits per 9 innings than his career average. He owns a career ERA+ of 114, but the last two years has been 125 and 157 apiece. The dude figured something out at age 26, and continues to improve. The most exciting statistic for Davies is how his K rate increased by nearly 1.75 per 9 inning last year. If he can maintain that, his hard hit % drops. As he's going to be 28, I think he's heading into his prime.
My optimistic prediction, he has a better season than Darvish does in San Diego.
Jake Arrieta:
Jake's had increasingly bad outings in Philly. His velocity has begun to dip. His H/9 rate has gone up by 1 each of the last 3 years. That said, he's kept the ball in the ballpark mostly, and his walk rate hasn't gotten out of control. His strikeouts have dipped, but despite that he's maintained a decent FIP.
Jake's BABIP was around .240 during his prime with the Cubs. With the Phillies the last two years it's been .316/.333. With an improved defense behind him and the ability to get back into a regular routine, I suspect he can keep that under .300, which would help a bit.
My optimistic prediction: he's a solid 3/4th starter in 2021. ERA around 4, and he'll eat some big innings.
Alec Mills:
Mills is a little bit of a mixed bag. The 4.48 ERA won't turn heads, especially backed with a 1.9 HR/9 rate while striking out just 6.6 batters per 9 innings. That said, he had a solid 1.155 WHIP in 2020, and now owns a MLB 1.17 WHIP. If he can keep the ball in the ballpark, he'll be alright. He had an alarming 21.3% HR/FB rate in 2020. Fortunately, his FB% was 33.2%. Not allowing hitters to elevate the ball off of him is going to be the key to his success.
My optimistic prediction: he maintains his stature as a solid bottom of the rotation kind of season. Think Jason Hammel in 2015. He showed enough in 2020 that I think he takes another step in '21
Adbert Azolay:
Alzolay pitched in just 6 games in 2020, yet accumulated .5 WAR (BBREF). That's a 2.5 WAR if he makes 30 starts. He had a solid ERA, FIP and WHIP. His HR/9 was a tiny .4. Even more exciting is his 11.2 K/9 rate in his 10 MLB games. His walk rate is a bit concerning, but he has swing and miss stuff. Alzolay also had a juicy 43.2% ground ball rate in 2020. His BABIP was .256, which is on par with Jake Arrieta in 2015. It shows that even when hitters made contact against him, it wasn't great.
My optimistic prediction, he establishes himself as a middle of the rotation starter this year, making us question if he can take another step or two into becoming a top of the rotation kinda guy.
Trevor Williams:
I can't beat around the bush. He's had back to back rough years, though his 2018 season was solid. Since then, he's allowed 3 more hits per 9 innings, and his home run rate has tripled. The Cubs have a great track record for taking fringe pitchers and getting them to improve. He's got the stuff to succeed.
In terms of pitch usage, he's got five of them: a four-seam fastball, sinker, slider, changeup and curve. Since his solid 2018, he's been throwing less and less sinkers, while throwing more sliders. Movement and velocity have been similar on all of his pitches year in and year out, so he hasn't lost a step. He's very coachable, and will likely bounce back.
Optimistic prediction: Depending on the health of others, he could be a solid spot starter. A low to mid 4 ERA for a 6th starter would be a win. I think he's capable of that.